#Bash 的 curl 命令
curl [OPTION]... URL
功能
通过 URL 从服务器传输数据或向服务器传输数据。
类型
可执行文件（/usr/bin/curl），属于 curl。
参数
使用 AI 翻译。
OPTION- 选项：--abstract-unix-socket <path>- 通过抽象 UNIX 域 Socket 连接--alt-svc <file name>- 使用该缓存文件启用 alt-svc--anyauth- 自动选择任意认证方式-a, --append- 上传时追加到目标文件--aws-sigv4 <provider1[:provider2[:region[:service]]]>- 使用 AWS V4 签名认证--basic- 使用 HTTP Basic 认证--ca-native- 使用操作系统原生 CA 证书--cacert <file>- 用于验证对端的 CA 证书文件--capath <dir>- 用于验证对端的 CA 证书目录-E, --cert <certificate[:password]>- 客户端证书文件及密码--cert-status- 通过 OCSP Staple 验证服务器证书状态--cert-type <type>- 证书类型（DER/PEM/ENG/P12）--ciphers <list of ciphers>- 指定使用的 SSL 加密套件--compressed- 请求压缩响应--compressed-ssh- 启用 SSH 压缩-K, --config <file>- 从文件读取配置--connect-timeout <fractional seconds>- 连接允许的最长时间--connect-to <HOST1:PORT1:HOST2:PORT2>- 连接到指定主机-C, --continue-at <offset>- 从指定偏移处继续传输-b, --cookie <data|filename>- 从字符串/文件发送 Cookie-c, --cookie-jar <filename>- 操作后将 Cookie 写入文件--create-dirs- 创建必要的本地目录结构--create-file-mode <mode>- 创建文件时的权限模式--crlf- 上传时将 LF 转换为 CRLF--crlfile <file>- 使用此 CRL 列表--curves <algorithm list>- 指定 (EC) TLS 密钥交换算法-d, --data <data>- HTTP POST 数据--data-ascii <data>- HTTP POST ASCII 数据--data-binary <data>- HTTP POST 二进制数据--data-raw <data>- HTTP POST 数据（允许使用 '@'）--data-urlencode <data>- URL 编码后的 HTTP POST 数据--delegation <LEVEL>- GSS-API 委托权限级别--digest- 使用 HTTP Digest 认证-q, --disable- 禁用 .curlrc--disable-eprt- 禁止使用 EPRT 或 LPRT--disable-epsv- 禁止使用 EPSV--disallow-username-in-url- 禁止 URL 中包含用户名--dns-interface <interface>- 指定 DNS 请求使用的接口--dns-ipv4-addr <address>- 指定 DNS 请求使用的 IPv4 地址--dns-ipv6-addr <address>- 指定 DNS 请求使用的 IPv6 地址--dns-servers <addresses>- 指定使用的 DNS 服务器--doh-cert-status- 通过 OCSP Staple 验证 DoH 服务器证书状态--doh-insecure- 允许不安全的 DoH 连接--doh-url <URL>- 使用 DoH 解析主机名-D, --dump-header <filename>- 将响应头写入文件--egd-file <file>- 用于随机数据的 EGD socket 路径--engine <name>- 使用的加密引擎--etag-compare <file>- 从文件读取 ETag 并作为自定义头发送--etag-save <file>- 从响应解析 ETag 并保存到文件--expect100-timeout <seconds>- 等待 100-continue 的时间-f, --fail- HTTP 错误时快速失败且不输出内容--fail-early- 传输中首次错误即失败，不继续--fail-with-body- HTTP 错误时失败但保留响应体--false-start- 启用 TLS False Start-F, --form <name=content>- 指定 multipart MIME 数据--form-escape- 使用反斜杠转义 multipart 表单字段/文件名--form-string <name=string>- 指定 multipart MIME 字符串数据--ftp-account <data>- FTP 账户数据字符串--ftp-alternative-to-user <command>- 替代 USER 命令的字符串--ftp-create-dirs- 若不存在则创建远程目录--ftp-method <method>- 控制 CWD 使用方式--ftp-pasv- 使用 PASV/EPSV 而非 PORT-P, --ftp-port <address>- 使用 PORT 而非 PASV--ftp-pret- 在 PASV 前发送 PRET--ftp-skip-pasv-ip- 忽略 PASV 返回的 IP 地址--ftp-ssl-ccc- 认证后发送 CCC--ftp-ssl-ccc-mode <active/passive>- 设置 CCC 模式--ftp-ssl-control- 登录使用 SSL/TLS，传输明文-G, --get- 将 POST 数据附加到 URL 并使用 GET-g, --globoff- 禁用 URL 中 {} 和 [] 的扩展--happy-eyeballs-timeout-ms <milliseconds>- IPv6 优先连接超时后切换 IPv4--haproxy-clientip- 在 HAProxy PROXY v1 头中设置客户端 IP--haproxy-protocol- 发送 HAProxy PROXY v1 头-I, --head- 仅显示响应头信息-H, --header <header/@file>- 向服务器发送自定义头-h, --help <category>- 获取命令帮助--hostpubmd5 <md5>- 主机公钥的 MD5 校验值--hostpubsha256 <sha256>- 主机公钥的 SHA256 校验值--hsts <file name>- 使用该缓存文件启用 HSTS--http0.9- 允许 HTTP 0.9 响应-0, --http1.0- 使用 HTTP 1.0--http1.1- 使用 HTTP 1.1--http2- 使用 HTTP/2--http2-prior-knowledge- 直接使用 HTTP/2（不升级）--http3- 使用 HTTP/3--http3-only- 仅使用 HTTP/3--ignore-content-length- 忽略远程资源大小-i, --include- 输出中包含响应头-k, --insecure- 允许不安全连接--interface <name>- 使用指定网络接口--ipfs-gateway <URL>- 指定 IPFS 网关-4, --ipv4- 解析为 IPv4-6, --ipv6- 解析为 IPv6--json <data>- 发送 JSON 格式 POST 数据-j, --junk-session-cookies- 忽略文件中的会话 Cookie--keepalive-time <seconds>- keepalive 探测间隔--key <key>- 私钥文件--key-type <type>- 私钥类型（DER/PEM/ENG）--krb <level>- 启用 Kerberos（安全级别）--libcurl <file>- 导出等效的 libcurl 代码--limit-rate <speed>- 限制传输速度-l, --list-only- 仅列出模式--local-port <num/range>- 指定本地端口范围-L, --location- 跟随重定向--location-trusted- 跟随重定向并发送认证信息--login-options <options>- 服务器登录选项--mail-auth <address>- 原始邮件发件人地址--mail-from <address>- 发件地址--mail-rcpt <address>- 收件地址--mail-rcpt-allowfails- 允许部分收件人失败-M, --manual- 显示完整手册--max-filesize <bytes>- 最大下载文件大小--max-redirs <num>- 最大重定向次数-m, --max-time <fractional seconds>- 最大传输时间--metalink- 将 URL 当作 metalink XML 文件处理--negotiate- 使用 HTTP Negotiate（SPNEGO）认证-n, --netrc- 必须从 .netrc 读取用户名和密码--netrc-file <filename>- 指定 netrc 文件--netrc-optional- 使用 .netrc 或 URL 中的凭据-:, --next- 下一个 URL 使用独立选项--no-alpn- 禁用 ALPN TLS 扩展-N, --no-buffer- 禁用输出缓冲--no-clobber- 不覆盖已存在文件--no-keepalive- 禁用 TCP keepalive--no-npn- 禁用 NPN TLS 扩展--no-progress-meter- 不显示进度条--no-sessionid- 禁用 SSL 会话复用--noproxy <no-proxy-list>- 不使用代理的主机列表--ntlm- 使用 HTTP NTLM 认证--ntlm-wb- 使用 winbind 的 NTLM 认证--oauth2-bearer <token>- OAuth2 Bearer Token-o, --output <file>- 输出到文件--output-dir <dir>- 指定输出目录-Z, --parallel- 并行执行传输--parallel-immediate- 立即并行（不等待复用）--parallel-max <num>- 最大并发传输数--pass <phrase>- 私钥密码--path-as-is- 不规范化 URL 路径中的 ..--pinnedpubkey <hashes>- 用于验证对端的公钥--post301- 遇到 301 时不切换为 GET--post302- 遇到 302 时不切换为 GET--post303- 遇到 303 时不切换为 GET--preproxy [protocol://]host[:port]- 使用前置代理-#, --progress-bar- 使用进度条显示传输--proto <protocols>- 启用/禁用指定协议--proto-default <protocol>- 为无协议的 URL 指定默认协议--proto-redir <protocols>- 重定向时启用/禁用协议-x, --proxy [protocol://]host[:port]- 使用代理服务器--proxy-anyauth- 自动选择任意代理认证方式--proxy-basic- 使用 Basic 代理认证--proxy-ca-native- 使用操作系统原生 CA 验证代理--proxy-cacert <file>- 用于验证代理的 CA 证书文件--proxy-capath <dir>- 用于验证代理的 CA 证书目录--proxy-cert <cert[:passwd]>- 代理客户端证书--proxy-cert-type <type>- 代理证书类型--proxy-ciphers <list>- 代理使用的 SSL 加密套件--proxy-crlfile <file>- 代理使用的 CRL 列表--proxy-digest- 使用 Digest 代理认证--proxy-header <header/@file>- 向代理发送自定义头--proxy-http2- HTTPS 代理使用 HTTP/2--proxy-insecure- 不验证代理证书--proxy-key <key>- 代理私钥文件--proxy-key-type <type>- 代理私钥类型--proxy-negotiate- 使用 SPNEGO 代理认证--proxy-ntlm- 使用 NTLM 代理认证--proxy-pass <phrase>- 代理私钥密码--proxy-pinnedpubkey <hashes>- 验证代理公钥--proxy-service-name <name>- SPNEGO 代理服务名称--proxy-ssl-allow-beast- 允许 BEAST 漏洞（兼容性）--proxy-ssl-auto-client-cert- 自动使用客户端证书（Schannel）--proxy-tls13-ciphers <ciphersuite list>- TLS 1.3 代理加密套件--proxy-tlsauthtype <type>- 代理 TLS 认证类型--proxy-tlspassword <string>- 代理 TLS 密码--proxy-tlsuser <name>- 代理 TLS 用户名--proxy-tlsv1- 代理连接使用 TLSv1-U, --proxy-user <user:password>- 代理用户名和密码--proxy1.0 <host[:port]>- 使用 HTTP/1.0 代理-p, --proxytunnel- 使用 HTTP CONNECT 建立隧道--pubkey <key>- SSH 公钥文件-Q, --quote <command>- 传输前向服务器发送命令--random-file <file>- 从文件读取随机数据-r, --range <range>- 仅获取指定字节范围--rate <max request rate>- 串行请求速率限制--raw- 使用原始 HTTP（不进行解码）-e, --referer <URL>- 设置 Referer 头-J, --remote-header-name- 使用响应头中的文件名-O, --remote-name- 使用远程文件名保存--remote-name-all- 所有 URL 使用远程文件名-R, --remote-time- 保留远程文件时间--remove-on-error- 出错时删除输出文件-X, --request <method>- 指定请求方法--request-target <path>- 指定请求目标路径--resolve <[+]host:port:addr[,addr]...>- 手动指定解析地址--retry <num>- 发生临时错误时重试--retry-all-errors- 重试所有错误--retry-connrefused- 连接被拒绝时重试--retry-delay <seconds>- 重试间隔时间--retry-max-time <seconds>- 最大重试时间--sasl-authzid <identity>- SASL PLAIN 认证身份--sasl-ir- 在 SASL 认证中启用初始响应--service-name <name>- SPNEGO 服务名称-S, --show-error- 即使使用 -s 也显示错误-s, --silent- 静默模式--socks4 <host[:port]>- 使用 SOCKS4 代理--socks4a <host[:port]>- 使用 SOCKS4a 代理--socks5 <host[:port]>- 使用 SOCKS5 代理--socks5-basic- SOCKS5 用户名/密码认证--socks5-gssapi- SOCKS5 使用 GSS-API 认证--socks5-gssapi-nec- 兼容 NEC SOCKS5 服务器--socks5-gssapi-service <name>- SOCKS5 GSS-API 服务名称--socks5-hostname <host[:port]>- SOCKS5 代理（传递主机名）-Y, --speed-limit <speed>- 低于该速度时中止传输-y, --speed-time <seconds>- 持续低速触发中止的时间--ssl- 尝试使用 SSL/TLS--ssl-allow-beast- 允许 BEAST 漏洞（兼容性）--ssl-auto-client-cert- 自动使用客户端证书（Schannel）--ssl-no-revoke- 禁用证书吊销检查（Schannel）--ssl-reqd- 强制使用 SSL/TLS--ssl-revoke-best-effort- 忽略 CRL 不可用情况（Schannel）-2, --sslv2- 使用 SSLv2-3, --sslv3- 使用 SSLv3--stderr <file>- 将错误输出重定向到文件--styled-output- 启用带样式的 HTTP 头输出--suppress-connect-headers- 抑制代理 CONNECT 响应头--tcp-fastopen- 使用 TCP Fast Open--tcp-nodelay- 使用 TCP_NODELAY 选项-t, --telnet-option <opt=val>- 设置 telnet 选项--tftp-blksize <value>- 设置 TFTP 块大小--tftp-no-options- 不发送 TFTP 选项-z, --time-cond <time>- 基于时间条件进行传输--tls-max <VERSION>- 设置最大 TLS 版本--tls13-ciphers <ciphersuite list>- TLS 1.3 加密套件--tlsauthtype <type>- TLS 认证类型--tlspassword <string>- TLS 密码--tlsuser <name>- TLS 用户名-1, --tlsv1- 使用 TLSv1.0 或更高版本--tlsv1.0- 使用 TLSv1.0 或更高版本--tlsv1.1- 使用 TLSv1.1 或更高版本--tlsv1.2- 使用 TLSv1.2 或更高版本--tlsv1.3- 使用 TLSv1.3 或更高版本--tr-encoding- 请求压缩传输编码--trace <file>- 将调试跟踪写入文件--trace-ascii <file>- 文本格式的调试跟踪--trace-config <string>- 配置 trace/verbose 输出内容--trace-ids- 在 trace/verbose 中添加连接标识--trace-time- 在 trace/verbose 中添加时间戳--unix-socket <path>- 通过 UNIX 域 Socket 连接-T, --upload-file <file>- 上传本地文件--url <url>- 指定 URL--url-query <data>- 添加 URL 查询参数-B, --use-ascii- 使用 ASCII 文本传输-u, --user <user:password>- 服务器用户名和密码-A, --user-agent <name>- 设置 User-Agent--variable <[%]name=text/@file>- 设置变量-v, --verbose- 输出详细调试信息-V, --version- 显示版本信息并退出-w, --write-out <format>- 完成后输出指定格式--xattr- 将元数据存储到扩展文件属性
URL- 目标的 URL
cURL 命令生成器
#示例
$ curl https://example.com
<!doctype html><html lang="en"><head><title>Example Domain</title><meta name="viewport" content="width=device-width, initial-scale=1"><style>body{background:#eee;width:60vw;margin:15vh auto;font-family:system-ui,sans-serif}h1{font-size:1.5em}div{opacity:0.8}a:link,a:visited{color:#348}</style></head><body><div><h1>Example Domain</h1><p>This domain is for use in documentation examples without needing permission. Avoid use in operations.</p><p><a href="https://iana.org/domains/example">Learn more</a></p></div></body></html>
#推荐阅读
#手册
curl(1) curl Manual curl(1)
NAME
curl - transfer a URL
SYNOPSIS
curl [options / URLs]
DESCRIPTION
curl is a tool for transferring data from or to a server using URLs. It
supports these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP,
HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP,
SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS.
curl is powered by libcurl for all transfer-related features. See
libcurl(3) for details.
URL
The URL syntax is protocol-dependent. You find a detailed description
in RFC 3986.
If you provide a URL without a leading protocol:// scheme, curl guesses
what protocol you want. It then defaults to HTTP but assumes others
based on often-used host name prefixes. For example, for host names
starting with "ftp." curl assumes you want FTP.
You can specify any amount of URLs on the command line. They are
fetched in a sequential manner in the specified order unless you use
-Z, --parallel. You can specify command line options and URLs mixed and
in any order on the command line.
curl attempts to reuse connections when doing multiple transfers, so
that getting many files from the same server do not use multiple con‐
nects and setup handshakes. This improves speed. Connection reuse can
only be done for URLs specified for a single command line invocation
and cannot be performed between separate curl runs.
Provide an IPv6 zone id in the URL with an escaped percentage sign.
Like in
"http://[fe80::3%25eth0]/"
Everything provided on the command line that is not a command line op‐
tion or its argument, curl assumes is a URL and treats it as such.
GLOBBING
You can specify multiple URLs or parts of URLs by writing lists within
braces or ranges within brackets. We call this "globbing".
Provide a list with three different names like this:
"http://site.{one,two,three}.com"
or you can get sequences of alphanumeric series by using [] as in:
"ftp://ftp.example.com/file[1-100].txt"
"ftp://ftp.example.com/file[001-100].txt" (with leading zeros)
"ftp://ftp.example.com/file[a-z].txt"
Nested sequences are not supported, but you can use several ones next
to each other:
"http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html"
You can specify a step counter for the ranges to get every Nth number
or letter:
"http://example.com/file[1-100:10].txt"
"http://example.com/file[a-z:2].txt"
When using [] or {} sequences when invoked from a command line prompt,
you probably have to put the full URL within double quotes to avoid the
shell from interfering with it. This also goes for other characters
treated special, like for example '&', '?' and '*'.
Switch off globbing with -g, --globoff.
VARIABLES
curl supports command line variables (added in 8.3.0). Set variables
with --variable name=content or --variable name@file (where "file" can
be stdin if set to a single dash (-)).
Variable contents can expanded in option parameters using "{{name}}"
(without the quotes) if the option name is prefixed with "--expand-".
This gets the contents of the variable "name" inserted, or a blank if
the name does not exist as a variable. Insert "{{" verbatim in the
string by prefixing it with a backslash, like "\{{".
You an access and expand environment variables by first importing them.
You can select to either require the environment variable to be set or
you can provide a default value in case it is not already set. Plain
--variable %name imports the variable called 'name' but exits with an
error if that environment variable is not already set. To provide a de‐
fault value if it is not set, use --variable %name=content or --vari‐
able %name@content.
Example. Get the USER environment variable into the URL, fail if USER
is not set:
--variable '%USER'
--expand-url = "https://example.com/api/{{USER}}/method"
When expanding variables, curl supports a set of functions that can
make the variable contents more convenient to use. It can trim leading
and trailing white space with trim, it can output the contents as a
JSON quoted string with json, URL encode the string with url or base64
encode it with b64. You apply function to a variable expansion, add
them colon separated to the right side of the variable. Variable con‐
tent holding null bytes that are not encoded when expanded cause error.
Example: get the contents of a file called $HOME/.secret into a vari‐
able called "fix". Make sure that the content is trimmed and per‐
cent-encoded sent as POST data:
--variable %HOME
--expand-variable fix@{{HOME}}/.secret
--expand-data "{{fix:trim:url}}"
https://example.com/
Command line variables and expansions were added in in 8.3.0.
OUTPUT
If not told otherwise, curl writes the received data to stdout. It can
be instructed to instead save that data into a local file, using the
-o, --output or -O, --remote-name options. If curl is given multiple
URLs to transfer on the command line, it similarly needs multiple op‐
tions for where to save them.
curl does not parse or otherwise "understand" the content it gets or
writes as output. It does no encoding or decoding, unless explicitly
asked to with dedicated command line options.
PROTOCOLS
curl supports numerous protocols, or put in URL terms: schemes. Your
particular build may not support them all.
DICT Lets you lookup words using online dictionaries.
FILE Read or write local files. curl does not support accessing
file:// URL remotely, but when running on Microsoft Windows us‐
ing the native UNC approach works.
FTP(S) curl supports the File Transfer Protocol with a lot of tweaks
and levers. With or without using TLS.
GOPHER(S)
Retrieve files.
HTTP(S)
curl supports HTTP with numerous options and variations. It can
speak HTTP version 0.9, 1.0, 1.1, 2 and 3 depending on build op‐
tions and the correct command line options.
IMAP(S)
Using the mail reading protocol, curl can "download" emails for
you. With or without using TLS.
LDAP(S)
curl can do directory lookups for you, with or without TLS.
MQTT curl supports MQTT version 3. Downloading over MQTT equals "sub‐
scribe" to a topic while uploading/posting equals "publish" on a
topic. MQTT over TLS is not supported (yet).
POP3(S)
Downloading from a pop3 server means getting a mail. With or
without using TLS.
RTMP(S)
The Realtime Messaging Protocol is primarily used to serve
streaming media and curl can download it.
RTSP curl supports RTSP 1.0 downloads.
SCP curl supports SSH version 2 scp transfers.
SFTP curl supports SFTP (draft 5) done over SSH version 2.
SMB(S) curl supports SMB version 1 for upload and download.
SMTP(S)
Uploading contents to an SMTP server means sending an email.
With or without TLS.
TELNET Telling curl to fetch a telnet URL starts an interactive session
where it sends what it reads on stdin and outputs what the
server sends it.
TFTP curl can do TFTP downloads and uploads.
PROGRESS METER
curl normally displays a progress meter during operations, indicating
the amount of transferred data, transfer speeds and estimated time
left, etc. The progress meter displays the transfer rate in bytes per
second. The suffixes (k, M, G, T, P) are 1024 based. For example 1k is
1024 bytes. 1M is 1048576 bytes.
curl displays this data to the terminal by default, so if you invoke
curl to do an operation and it is about to write data to the terminal,
it disables the progress meter as otherwise it would mess up the output
mixing progress meter and response data.
If you want a progress meter for HTTP POST or PUT requests, you need to
redirect the response output to a file, using shell redirect (>), -o,
--output or similar.
This does not apply to FTP upload as that operation does not spit out
any response data to the terminal.
If you prefer a progress "bar" instead of the regular meter, -#,
--progress-bar is your friend. You can also disable the progress meter
completely with the -s, --silent option.
VERSION
This man page describes curl 8.5.0. If you use a later version, chances
are this man page does not fully document it. If you use an earlier
version, this document tries to include version information about which
specific version that introduced changes.
You can always learn which the latest curl version is by running
curl https://curl.se/info
The online version of this man page is always showing the latest incar‐
nation: https://curl.se/docs/manpage.html
OPTIONS
Options start with one or two dashes. Many of the options require an
additional value next to them. If provided text does not start with a
dash, it is presumed to be and treated as a URL.
The short "single-dash" form of the options, -d for example, may be
used with or without a space between it and its value, although a space
is a recommended separator. The long "double-dash" form, -d, --data for
example, requires a space between it and its value.
Short version options that do not need any additional values can be
used immediately next to each other, like for example you can specify
all the options -O, -L and -v at once as -OLv.
In general, all boolean options are enabled with --option and yet again
disabled with --no-option. That is, you use the same option name but
prefix it with "no-". However, in this list we mostly only list and
show the --option version of them.
When -:, --next is used, it resets the parser state and you start again
with a clean option state, except for the options that are "global".
Global options retain their values and meaning even after -:, --next.
The following options are global: --fail-early, --libcurl, --paral‐
lel-immediate, -Z, --parallel, -#, --progress-bar, --rate, -S,
--show-error, --stderr, --styled-output, --trace-ascii, --trace-config,
--trace-ids, --trace-time, --trace and -v, --verbose.
--abstract-unix-socket <path>
(HTTP) Connect through an abstract Unix domain socket, instead
of using the network. Note: netstat shows the path of an ab‐
stract socket prefixed with '@', however the <path> argument
should not have this leading character.
If --abstract-unix-socket is provided several times, the last
set value is used.
Example:
curl --abstract-unix-socket socketpath https://example.com
See also --unix-socket. Added in 7.53.0.
--alt-svc <file name>
(HTTPS) This option enables the alt-svc parser in curl. If the
file name points to an existing alt-svc cache file, that gets
used. After a completed transfer, the cache is saved to the file
name again if it has been modified.
Specify a "" file name (zero length) to avoid loading/saving and
make curl just handle the cache in memory.
If this option is used several times, curl loads contents from
all the files but the last one is used for saving.
--alt-svc can be used several times in a command line
Example:
curl --alt-svc svc.txt https://example.com
See also --resolve and --connect-to. Added in 7.64.1.
--anyauth
(HTTP) Tells curl to figure out authentication method by itself,
and use the most secure one the remote site claims to support.
This is done by first doing a request and checking the re‐
sponse-headers, thus possibly inducing an extra network
round-trip. This is used instead of setting a specific authenti‐
cation method, which you can do with --basic, --digest, --ntlm,
and --negotiate.
Using --anyauth is not recommended if you do uploads from stdin,
since it may require data to be sent twice and then the client
must be able to rewind. If the need should arise when uploading
from stdin, the upload operation fails.
Used together with -u, --user.
Providing --anyauth multiple times has no extra effect.
Example:
curl --anyauth --user me:pwd https://example.com
See also --proxy-anyauth, --basic and --digest.
-a, --append
(FTP SFTP) When used in an upload, this option makes curl append
to the target file instead of overwriting it. If the remote file
does not exist, it is created. Note that this flag is ignored by
some SFTP servers (including OpenSSH).
Providing -a, --append multiple times has no extra effect. Dis‐
able it again with --no-append.
Example:
curl --upload-file local --append ftp://example.com/
See also -r, --range and -C, --continue-at.
--aws-sigv4 <provider1[:provider2[:region[:service]]]>
Use AWS V4 signature authentication in the transfer.
The provider argument is a string that is used by the algorithm
when creating outgoing authentication headers.
The region argument is a string that points to a geographic area
of a resources collection (region-code) when the region name is
omitted from the endpoint.
The service argument is a string that points to a function pro‐
vided by a cloud (service-code) when the service name is omitted
from the endpoint.
If --aws-sigv4 is provided several times, the last set value is
used.
Example:
curl --aws-sigv4 "aws:amz:us-east-2:es" --user "key:secret" https://example.com
See also --basic and -u, --user. Added in 7.75.0.
--basic
(HTTP) Tells curl to use HTTP Basic authentication with the re‐
mote host. This is the default and this option is usually point‐
less, unless you use it to override a previously set option that
sets a different authentication method (such as --ntlm, --di‐
gest, or --negotiate).
Used together with -u, --user.
Providing --basic multiple times has no extra effect.
Example:
curl -u name:password --basic https://example.com
See also --proxy-basic.
--ca-native
(TLS) Tells curl to use the CA store from the native operating
system to verify the peer. By default, curl otherwise uses a CA
store provided in a single file or directory, but when using
this option it interfaces the operating system's own vault.
This option only works for curl on Windows when built to use
OpenSSL. When curl on Windows is built to use Schannel, this
feature is implied and curl then only uses the native CA store.
curl built with wolfSSL also supports this option (added in
8.3.0).
Providing --ca-native multiple times has no extra effect. Dis‐
able it again with --no-ca-native.
Example:
curl --ca-native https://example.com
See also --cacert, --capath and -k, --insecure. Added in 8.2.0.
--cacert <file>
(TLS) Tells curl to use the specified certificate file to verify
the peer. The file may contain multiple CA certificates. The
certificate(s) must be in PEM format. Normally curl is built to
use a default file for this, so this option is typically used to
alter that default file.
curl recognizes the environment variable named 'CURL_CA_BUNDLE'
if it is set, and uses the given path as a path to a CA cert
bundle. This option overrides that variable.
The windows version of curl automatically looks for a CA certs
file named 'curl-ca-bundle.crt', either in the same directory as
curl.exe, or in the Current Working Directory, or in any folder
along your PATH.
(iOS and macOS only) If curl is built against Secure Transport,
then this option is supported for backward compatibility with
other SSL engines, but it should not be set. If the option is
not set, then curl uses the certificates in the system and user
Keychain to verify the peer, which is the preferred method of
verifying the peer's certificate chain.
(Schannel only) This option is supported for Schannel in Windows
7 or later (added in 7.60.0). This option is supported for back‐
ward compatibility with other SSL engines; instead it is recom‐
mended to use Windows' store of root certificates (the default
for Schannel).
If --cacert is provided several times, the last set value is
used.
Example:
curl --cacert CA-file.txt https://example.com
See also --capath and -k, --insecure.
--capath <dir>
(TLS) Tells curl to use the specified certificate directory to
verify the peer. Multiple paths can be provided by separating
them with ":" (e.g. "path1:path2:path3"). The certificates must
be in PEM format, and if curl is built against OpenSSL, the di‐
rectory must have been processed using the c_rehash utility sup‐
plied with OpenSSL. Using --capath can allow OpenSSL-powered
curl to make SSL-connections much more efficiently than using
--cacert if the --cacert file contains many CA certificates.
If this option is set, the default capath value is ignored.
If --capath is provided several times, the last set value is
used.
Example:
curl --capath /local/directory https://example.com
See also --cacert and -k, --insecure.
--cert-status
(TLS) Tells curl to verify the status of the server certificate
by using the Certificate Status Request (aka. OCSP stapling) TLS
extension.
If this option is enabled and the server sends an invalid (e.g.
expired) response, if the response suggests that the server cer‐
tificate has been revoked, or no response at all is received,
the verification fails.
This is currently only implemented in the OpenSSL and GnuTLS
backends.
Providing --cert-status multiple times has no extra effect.
Disable it again with --no-cert-status.
Example:
curl --cert-status https://example.com
See also --pinnedpubkey.
--cert-type <type>
(TLS) Tells curl what type the provided client certificate is
using. PEM, DER, ENG and P12 are recognized types.
The default type depends on the TLS backend and is usually PEM,
however for Secure Transport and Schannel it is P12. If -E,
--cert is a pkcs11: URI then ENG is the default type.
If --cert-type is provided several times, the last set value is
used.
Example:
curl --cert-type PEM --cert file https://example.com
See also -E, --cert, --key and --key-type.
-E, --cert <certificate[:password]>
(TLS) Tells curl to use the specified client certificate file
when getting a file with HTTPS, FTPS or another SSL-based proto‐
col. The certificate must be in PKCS#12 format if using Secure
Transport, or PEM format if using any other engine. If the op‐
tional password is not specified, it is queried for on the ter‐
minal. Note that this option assumes a certificate file that is
the private key and the client certificate concatenated. See -E,
--cert and --key to specify them independently.
In the <certificate> portion of the argument, you must escape
the character ":" as "\:" so that it is not recognized as the
password delimiter. Similarly, you must escape the character "\"
as "\\" so that it is not recognized as an escape character.
If curl is built against OpenSSL library, and the engine pkcs11
is available, then a PKCS#11 URI (RFC 7512) can be used to spec‐
ify a certificate located in a PKCS#11 device. A string begin‐
ning with "pkcs11:" is interpreted as a PKCS#11 URI. If a
PKCS#11 URI is provided, then the --engine option is set as
"pkcs11" if none was provided and the --cert-type option is set
as "ENG" if none was provided.
(iOS and macOS only) If curl is built against Secure Transport,
then the certificate string can either be the name of a certifi‐
cate/private key in the system or user keychain, or the path to
a PKCS#12-encoded certificate and private key. If you want to
use a file from the current directory, please precede it with
"./" prefix, in order to avoid confusion with a nickname.
(Schannel only) Client certificates must be specified by a path
expression to a certificate store. (Loading PFX is not sup‐
ported; you can import it to a store first). You can use "<store
location>\<store name>\<thumbprint>" to refer to a certificate
in the system certificates store, for example, "Curren‐
tUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a". Thumbprint
is usually a SHA-1 hex string which you can see in certificate
details. Following store locations are supported: CurrentUser,
LocalMachine, CurrentService, Services, CurrentUserGroupPolicy,
LocalMachineGroupPolicy and LocalMachineEnterprise.
If -E, --cert is provided several times, the last set value is
used.
Example:
curl --cert certfile --key keyfile https://example.com
See also --cert-type, --key and --key-type.
--ciphers <list of ciphers>
(TLS) Specifies which ciphers to use in the connection. The list
of ciphers must specify valid ciphers. Read up on SSL cipher
list details on this URL:
https://curl.se/docs/ssl-ciphers.html
If --ciphers is provided several times, the last set value is
used.
Example:
curl --ciphers ECDHE-ECDSA-AES256-CCM8 https://example.com
See also --tlsv1.3, --tls13-ciphers and --proxy-ciphers.
--compressed-ssh
(SCP SFTP) Enables built-in SSH compression. This is a request,
not an order; the server may or may not do it.
Providing --compressed-ssh multiple times has no extra effect.
Disable it again with --no-compressed-ssh.
Example:
curl --compressed-ssh sftp://example.com/
See also --compressed. Added in 7.56.0.
--compressed
(HTTP) Request a compressed response using one of the algorithms
curl supports, and automatically decompress the content.
Response headers are not modified when saved, so if they are
"interpreted" separately again at a later point they might ap‐
pear to be saying that the content is (still) compressed; while
in fact it has already been decompressed.
If this option is used and the server sends an unsupported en‐
coding, curl reports an error. This is a request, not an order;
the server may or may not deliver data compressed.
Providing --compressed multiple times has no extra effect. Dis‐
able it again with --no-compressed.
Example:
curl --compressed https://example.com
See also --compressed-ssh.
-K, --config <file>
Specify a text file to read curl arguments from. The command
line arguments found in the text file are used as if they were
provided on the command line.
Options and their parameters must be specified on the same line
in the file, separated by whitespace, colon, or the equals sign.
Long option names can optionally be given in the config file
without the initial double dashes and if so, the colon or equals
characters can be used as separators. If the option is specified
with one or two dashes, there can be no colon or equals charac‐
ter between the option and its parameter.
If the parameter contains whitespace or starts with a colon (:)
or equals sign (=), it must be specified enclosed within double
quotes ("). Within double quotes the following escape sequences
are available: \\, \", \t, \n, \r and \v. A backslash preceding
any other letter is ignored.
If the first non-blank column of a config line is a '#' charac‐
ter, that line is treated as a comment.
Only write one option per physical line in the config file. A
single line is required to be no more than 10 megabytes (since
8.2.0).
Specify the filename to -K, --config as '-' to make curl read
the file from stdin.
Note that to be able to specify a URL in the config file, you
need to specify it using the --url option, and not by simply
writing the URL on its own line. So, it could look similar to
this:
url = "https://curl.se/docs/"
# --- Example file ---
# this is a comment
url = "example.com"
output = "curlhere.html"
user-agent = "superagent/1.0"
# and fetch another URL too
url = "example.com/docs/manpage.html"
-O
referer = "http://nowhereatall.example.com/"
# --- End of example file ---
When curl is invoked, it (unless -q, --disable is used) checks
for a default config file and uses it if found, even when -K,
--config is used. The default config file is checked for in the
following places in this order:
1) "$CURL_HOME/.curlrc"
2) "$XDG_CONFIG_HOME/curlrc" (Added in 7.73.0)
3) "$HOME/.curlrc"
4) Windows: "%USERPROFILE%\.curlrc"
5) Windows: "%APPDATA%\.curlrc"
6) Windows: "%USERPROFILE%\Application Data\.curlrc"
7) Non-Windows: use getpwuid to find the home directory
8) On Windows, if it finds no .curlrc file in the sequence de‐
scribed above, it checks for one in the same dir the curl exe‐
cutable is placed.
On Windows two filenames are checked per location: .curlrc and
_curlrc, preferring the former. Older versions on Windows
checked for _curlrc only.
-K, --config can be used several times in a command line
Example:
curl --config file.txt https://example.com
See also -q, --disable.
--connect-timeout <fractional seconds>
Maximum time in seconds that you allow curl's connection to
take. This only limits the connection phase, so if curl con‐
nects within the given period it continues - if not it exits.
This option accepts decimal values. The decimal value needs to
be provided using a dot (.) as decimal separator - not the local
version even if it might be using another separator.
The connection phase is considered complete when the DNS lookup
and requested TCP, TLS or QUIC handshakes are done.
If --connect-timeout is provided several times, the last set
value is used.
Examples:
curl --connect-timeout 20 https://example.com
curl --connect-timeout 3.14 https://example.com
See also -m, --max-time.
--connect-to <HOST1:PORT1:HOST2:PORT2>
For a request to the given HOST1:PORT1 pair, connect to
HOST2:PORT2 instead. This option is suitable to direct requests
at a specific server, e.g. at a specific cluster node in a clus‐
ter of servers. This option is only used to establish the net‐
work connection. It does NOT affect the hostname/port that is
used for TLS/SSL (e.g. SNI, certificate verification) or for the
application protocols. "HOST1" and "PORT1" may be the empty
string, meaning "any host/port". "HOST2" and "PORT2" may also be
the empty string, meaning "use the request's original
host/port".
A "host" specified to this option is compared as a string, so it
needs to match the name used in request URL. It can be either
numerical such as "127.0.0.1" or the full host name such as "ex‐
ample.org".
--connect-to can be used several times in a command line
Example:
curl --connect-to example.com:443:example.net:8443 https://example.com
See also --resolve and -H, --header.
-C, --continue-at <offset>
Continue/Resume a previous file transfer at the given offset.
The given offset is the exact number of bytes that are skipped,
counting from the beginning of the source file before it is
transferred to the destination. If used with uploads, the FTP
server command SIZE is not used by curl.
Use "-C -" to tell curl to automatically find out where/how to
resume the transfer. It then uses the given output/input files
to figure that out.
If -C, --continue-at is provided several times, the last set
value is used.
Examples:
curl -C - https://example.com
curl -C 400 https://example.com
See also -r, --range.
-c, --cookie-jar <filename>
(HTTP) Specify to which file you want curl to write all cookies
after a completed operation. Curl writes all cookies from its
in-memory cookie storage to the given file at the end of opera‐
tions. If no cookies are known, no data is written. The file is
created using the Netscape cookie file format. If you set the
file name to a single dash, "-", the cookies are written to std‐
out.
The file specified with -c, --cookie-jar is only used for out‐
put. No cookies are read from the file. To read cookies, use the
-b, --cookie option. Both options can specify the same file.
This command line option activates the cookie engine that makes
curl record and use cookies. The -b, --cookie option also acti‐
vates it.
If the cookie jar cannot be created or written to, the whole
curl operation does not fail or even report an error clearly.
Using -v, --verbose gets a warning displayed, but that is the
only visible feedback you get about this possibly lethal situa‐
tion.
If -c, --cookie-jar is provided several times, the last set
value is used.
Examples:
curl -c store-here.txt https://example.com
curl -c store-here.txt -b read-these https://example.com
See also -b, --cookie.
-b, --cookie <data|filename>
(HTTP) Pass the data to the HTTP server in the Cookie header. It
is supposedly the data previously received from the server in a
"Set-Cookie:" line. The data should be in the format
"NAME1=VALUE1; NAME2=VALUE2". This makes curl use the cookie
header with this content explicitly in all outgoing request(s).
If multiple requests are done due to authentication, followed
redirects or similar, they all get this cookie passed on.
If no '=' symbol is used in the argument, it is instead treated
as a filename to read previously stored cookie from. This option
also activates the cookie engine which makes curl record incom‐
ing cookies, which may be handy if you are using this in combi‐
nation with the -L, --location option or do multiple URL trans‐
fers on the same invoke. If the file name is exactly a minus
("-"), curl instead reads the contents from stdin.
The file format of the file to read cookies from should be plain
HTTP headers (Set-Cookie style) or the Netscape/Mozilla cookie
file format.
The file specified with -b, --cookie is only used as input. No
cookies are written to the file. To store cookies, use the -c,
--cookie-jar option.
If you use the Set-Cookie file format and do not specify a do‐
main then the cookie is not sent since the domain never matches.
To address this, set a domain in Set-Cookie line (doing that in‐
cludes subdomains) or preferably: use the Netscape format.
Users often want to both read cookies from a file and write up‐
dated cookies back to a file, so using both -b, --cookie and -c,
--cookie-jar in the same command line is common.
-b, --cookie can be used several times in a command line
Examples:
curl -b cookiefile https://example.com
curl -b cookiefile -c cookiefile https://example.com
See also -c, --cookie-jar and -j, --junk-session-cookies.
--create-dirs
When used in conjunction with the -o, --output option, curl cre‐
ates the necessary local directory hierarchy as needed. This op‐
tion creates the directories mentioned with the -o, --output op‐
tion combined with the path possibly set with --output-dir. If
the combined output file name uses no directory, or if the di‐
rectories it mentions already exist, no directories are created.
Created directories are made with mode 0750 on unix style file
systems.
To create remote directories when using FTP or SFTP, try
--ftp-create-dirs.
Providing --create-dirs multiple times has no extra effect.
Disable it again with --no-create-dirs.
Example:
curl --create-dirs --output local/dir/file https://example.com
See also --ftp-create-dirs and --output-dir.
--create-file-mode <mode>
(SFTP SCP FILE) When curl is used to create files remotely using
one of the supported protocols, this option allows the user to
set which 'mode' to set on the file at creation time, instead of
the default 0644.
This option takes an octal number as argument.
If --create-file-mode is provided several times, the last set
value is used.
Example:
curl --create-file-mode 0777 -T localfile sftp://example.com/new
See also --ftp-create-dirs. Added in 7.75.0.
--crlf (FTP SMTP) Convert line feeds to carriage return plus line feeds
in upload. Useful for MVS (OS/390).
(SMTP added in 7.40.0)
Providing --crlf multiple times has no extra effect. Disable it
again with --no-crlf.
Example:
curl --crlf -T file ftp://example.com/
See also -B, --use-ascii.
--crlfile <file>
(TLS) Provide a file using PEM format with a Certificate Revoca‐
tion List that may specify peer certificates that are to be con‐
sidered revoked.
If --crlfile is provided several times, the last set value is
used.
Example:
curl --crlfile rejects.txt https://example.com
See also --cacert and --capath.
--curves <algorithm list>
(TLS) Tells curl to request specific curves to use during SSL
session establishment according to RFC 8422, 5.1. Multiple al‐
gorithms can be provided by separating them with ":" (e.g.
"X25519:P-521"). The parameter is available identically in the
"openssl s_client/s_server" utilities.
--curves allows a OpenSSL powered curl to make SSL-connections
with exactly the (EC) curve requested by the client, avoiding
nontransparent client/server negotiations.
If this option is set, the default curves list built into
OpenSSL are ignored.
If --curves is provided several times, the last set value is
used.
Example:
curl --curves X25519 https://example.com
See also --ciphers. Added in 7.73.0.
--data-ascii <data>
(HTTP) This is just an alias for -d, --data.
--data-ascii can be used several times in a command line
Example:
curl --data-ascii @file https://example.com
See also --data-binary, --data-raw and --data-urlencode.
--data-binary <data>
(HTTP) This posts data exactly as specified with no extra pro‐
cessing whatsoever.
If you start the data with the letter @, the rest should be a
filename. Data is posted in a similar manner as -d, --data does,
except that newlines and carriage returns are preserved and con‐
versions are never done.
Like -d, --data the default content-type sent to the server is
application/x-www-form-urlencoded. If you want the data to be
treated as arbitrary binary data by the server then set the con‐
tent-type to octet-stream: -H "Content-Type: applica‐
tion/octet-stream".
If this option is used several times, the ones following the
first append data as described in -d, --data.
--data-binary can be used several times in a command line
Example:
curl --data-binary @filename https://example.com
See also --data-ascii.
--data-raw <data>
(HTTP) This posts data similarly to -d, --data but without the
special interpretation of the @ character.
--data-raw can be used several times in a command line
Examples:
curl --data-raw "hello" https://example.com
curl --data-raw "@at@at@" https://example.com
See also -d, --data.
--data-urlencode <data>
(HTTP) This posts data, similar to the other -d, --data options
with the exception that this performs URL-encoding.
To be CGI-compliant, the <data> part should begin with a name
followed by a separator and a content specification. The <data>
part can be passed to curl using one of the following syntaxes:
content
This makes curl URL-encode the content and pass that on.
Just be careful so that the content does not contain any
= or @ symbols, as that makes the syntax match one of the
other cases below!
=content
This makes curl URL-encode the content and pass that on.
The preceding = symbol is not included in the data.
name=content
This makes curl URL-encode the content part and pass that
on. Note that the name part is expected to be URL-encoded
already.
@filename
This makes curl load data from the given file (including
any newlines), URL-encode that data and pass it on in the
POST.
name@filename
This makes curl load data from the given file (including
any newlines), URL-encode that data and pass it on in the
POST. The name part gets an equal sign appended, result‐
ing in name=urlencoded-file-content. Note that the name
is expected to be URL-encoded already.
--data-urlencode can be used several times in a command line
Examples:
curl --data-urlencode name=val https://example.com
curl --data-urlencode =encodethis https://example.com
curl --data-urlencode name@file https://example.com
curl --data-urlencode @fileonly https://example.com
See also -d, --data and --data-raw.
-d, --data <data>
(HTTP MQTT) Sends the specified data in a POST request to the
HTTP server, in the same way that a browser does when a user has
filled in an HTML form and presses the submit button. This makes
curl pass the data to the server using the content-type applica‐
tion/x-www-form-urlencoded. Compare to -F, --form.
--data-raw is almost the same but does not have a special inter‐
pretation of the @ character. To post data purely binary, you
should instead use the --data-binary option. To URL-encode the
value of a form field you may use --data-urlencode.
If any of these options is used more than once on the same com‐
mand line, the data pieces specified are merged with a separat‐
ing &-symbol. Thus, using '-d name=daniel -d skill=lousy' would
generate a post chunk that looks like 'name=daniel&skill=lousy'.
If you start the data with the letter @, the rest should be a
file name to read the data from, or - if you want curl to read
the data from stdin. Posting data from a file named 'foobar'
would thus be done with -d, --data @foobar. When -d, --data is
told to read from a file like that, carriage returns and new‐
lines are stripped out. If you do not want the @ character to
have a special interpretation use --data-raw instead.
The data for this option is passed on to the server exactly as
provided on the command line. curl does not convert, change or
improve it. It is up to the user to provide the data in the cor‐
rect form.
-d, --data can be used several times in a command line
Examples:
curl -d "name=curl" https://example.com
curl -d "name=curl" -d "tool=cmdline" https://example.com
curl -d @filename https://example.com
See also --data-binary, --data-urlencode and --data-raw. This
option is mutually exclusive to -F, --form and -I, --head and
-T, --upload-file.
--delegation <LEVEL>
(GSS/kerberos) Set LEVEL to tell the server what it is allowed
to delegate when it comes to user credentials.
none Do not allow any delegation.
policy Delegates if and only if the OK-AS-DELEGATE flag is set
in the Kerberos service ticket, which is a matter of
realm policy.
always Unconditionally allow the server to delegate.
If --delegation is provided several times, the last set value is
used.
Example:
curl --delegation "none" https://example.com
See also -k, --insecure and --ssl.
--digest
(HTTP) Enables HTTP Digest authentication. This is an authenti‐
cation scheme that prevents the password from being sent over
the wire in clear text. Use this in combination with the normal
-u, --user option to set user name and password.
Providing --digest multiple times has no extra effect. Disable
it again with --no-digest.
Example:
curl -u name:password --digest https://example.com
See also -u, --user, --proxy-digest and --anyauth. This option
is mutually exclusive to --basic and --ntlm and --negotiate.
--disable-eprt
(FTP) Tell curl to disable the use of the EPRT and LPRT commands
when doing active FTP transfers. Curl normally first attempts to
use EPRT before using PORT, but with this option, it uses PORT
right away. EPRT is an extension to the original FTP protocol,
and does not work on all servers, but enables more functionality
in a better way than the traditional PORT command.
--eprt can be used to explicitly enable EPRT again and --no-eprt
is an alias for --disable-eprt.
If the server is accessed using IPv6, this option has no effect
as EPRT is necessary then.
Disabling EPRT only changes the active behavior. If you want to
switch to passive mode you need to not use -P, --ftp-port or
force it with --ftp-pasv.
Providing --disable-eprt multiple times has no extra effect.
Disable it again with --no-disable-eprt.
Example:
curl --disable-eprt ftp://example.com/
See also --disable-epsv and -P, --ftp-port.
--disable-epsv
(FTP) Tell curl to disable the use of the EPSV command when do‐
ing passive FTP transfers. Curl normally first attempts to use
EPSV before PASV, but with this option, it does not try EPSV.
--epsv can be used to explicitly enable EPSV again and --no-epsv
is an alias for --disable-epsv.
If the server is an IPv6 host, this option has no effect as EPSV
is necessary then.
Disabling EPSV only changes the passive behavior. If you want to
switch to active mode you need to use -P, --ftp-port.
Providing --disable-epsv multiple times has no extra effect.
Disable it again with --no-disable-epsv.
Example:
curl --disable-epsv ftp://example.com/
See also --disable-eprt and -P, --ftp-port.
-q, --disable
If used as the first parameter on the command line, the curlrc
config file is not read or used. See the -K, --config for de‐
tails on the default config file search path.
Prior to 7.50.0 curl supported the short option name q but not
the long option name disable.
Providing -q, --disable multiple times has no extra effect.
Disable it again with --no-disable.
Example:
curl -q https://example.com
See also -K, --config.
--disallow-username-in-url
(HTTP) This tells curl to exit if passed a URL containing a
username. This is probably most useful when the URL is being
provided at runtime or similar.
Providing --disallow-username-in-url multiple times has no extra
effect. Disable it again with --no-disallow-username-in-url.
Example:
curl --disallow-username-in-url https://example.com
See also --proto. Added in 7.61.0.
--dns-interface <interface>
(DNS) Tell curl to send outgoing DNS requests through <inter‐
face>. This option is a counterpart to --interface (which does
not affect DNS). The supplied string must be an interface name
(not an address).
If --dns-interface is provided several times, the last set value
is used.
Example:
curl --dns-interface eth0 https://example.com
See also --dns-ipv4-addr and --dns-ipv6-addr. --dns-interface
requires that the underlying libcurl was built to support c-
ares.
--dns-ipv4-addr <address>
(DNS) Tell curl to bind to a specific IP address when making
IPv4 DNS requests, so that the DNS requests originate from this
address. The argument should be a single IPv4 address.
If --dns-ipv4-addr is provided several times, the last set value
is used.
Example:
curl --dns-ipv4-addr 10.1.2.3 https://example.com
See also --dns-interface and --dns-ipv6-addr. --dns-ipv4-addr
requires that the underlying libcurl was built to support c-
ares.
--dns-ipv6-addr <address>
(DNS) Tell curl to bind to a specific IP address when making
IPv6 DNS requests, so that the DNS requests originate from this
address. The argument should be a single IPv6 address.
If --dns-ipv6-addr is provided several times, the last set value
is used.
Example:
curl --dns-ipv6-addr 2a04:4e42::561 https://example.com
See also --dns-interface and --dns-ipv4-addr. --dns-ipv6-addr
requires that the underlying libcurl was built to support c-
ares.
--dns-servers <addresses>
Set the list of DNS servers to be used instead of the system de‐
fault. The list of IP addresses should be separated with com‐
mas. Port numbers may also optionally be given as :<port-number>
after each IP address.
If --dns-servers is provided several times, the last set value
is used.
Example:
curl --dns-servers 192.168.0.1,192.168.0.2 https://example.com
See also --dns-interface and --dns-ipv4-addr. --dns-servers re‐
quires that the underlying libcurl was built to support c-ares.
--doh-cert-status
Same as --cert-status but used for DoH (DNS-over-HTTPS).
Providing --doh-cert-status multiple times has no extra effect.
Disable it again with --no-doh-cert-status.
Example:
curl --doh-cert-status --doh-url https://doh.example https://example.com
See also --doh-insecure. Added in 7.76.0.
--doh-insecure
Same as -k, --insecure but used for DoH (DNS-over-HTTPS).
Providing --doh-insecure multiple times has no extra effect.
Disable it again with --no-doh-insecure.
Example:
curl --doh-insecure --doh-url https://doh.example https://example.com
See also --doh-url. Added in 7.76.0.
--doh-url <URL>
Specifies which DNS-over-HTTPS (DoH) server to use to resolve
hostnames, instead of using the default name resolver mechanism.
The URL must be HTTPS.
Some SSL options that you set for your transfer also applies to
DoH since the name lookups take place over SSL. However, the
certificate verification settings are not inherited but are con‐
trolled separately via --doh-insecure and --doh-cert-status.
This option is unset if an empty string "" is used as the URL.
(Added in 7.85.0)
If --doh-url is provided several times, the last set value is
used.
Example:
curl --doh-url https://doh.example https://example.com
See also --doh-insecure. Added in 7.62.0.
-D, --dump-header <filename>
(HTTP FTP) Write the received protocol headers to the specified
file. If no headers are received, the use of this option creates
an empty file.
When used in FTP, the FTP server response lines are considered
being "headers" and thus are saved there.
Having multiple transfers in one set of operations (i.e. the
URLs in one -:, --next clause), appends them to the same file,
separated by a blank line.
If -D, --dump-header is provided several times, the last set
value is used.
Example:
curl --dump-header store.txt https://example.com
See also -o, --output.
--egd-file <file>
(TLS) Deprecated option (added in 7.84.0). Prior to that it only
had an effect on curl if built to use old versions of OpenSSL.
Specify the path name to the Entropy Gathering Daemon socket.
The socket is used to seed the random engine for SSL connec‐
tions.
If --egd-file is provided several times, the last set value is
used.
Example:
curl --egd-file /random/here https://example.com
See also --random-file.
--engine <name>
(TLS) Select the OpenSSL crypto engine to use for cipher opera‐
tions. Use --engine list to print a list of build-time supported
engines. Note that not all (and possibly none) of the engines
may be available at runtime.
If --engine is provided several times, the last set value is
used.
Example:
curl --engine flavor https://example.com
See also --ciphers and --curves.
--etag-compare <file>
(HTTP) This option makes a conditional HTTP request for the spe‐
cific ETag read from the given file by sending a custom
If-None-Match header using the stored ETag.
For correct results, make sure that the specified file contains
only a single line with the desired ETag. An empty file is
parsed as an empty ETag.
Use the option --etag-save to first save the ETag from a re‐
sponse, and then use this option to compare against the saved
ETag in a subsequent request.
If --etag-compare is provided several times, the last set value
is used.
Example:
curl --etag-compare etag.txt https://example.com
See also --etag-save and -z, --time-cond. Added in 7.68.0.
--etag-save <file>
(HTTP) This option saves an HTTP ETag to the specified file. An
ETag is a caching related header, usually returned in a re‐
sponse.
If no ETag is sent by the server, an empty file is created.
If --etag-save is provided several times, the last set value is
used.
Example:
curl --etag-save storetag.txt https://example.com
See also --etag-compare. Added in 7.68.0.
--expect100-timeout <seconds>
(HTTP) Maximum time in seconds that you allow curl to wait for a
100-continue response when curl emits an Expects: 100-continue
header in its request. By default curl waits one second. This
option accepts decimal values! When curl stops waiting, it con‐
tinues as if the response has been received.
The decimal value needs to provided using a dot (.) as decimal
separator - not the local version even if it might be using an‐
other separator.
If --expect100-timeout is provided several times, the last set
value is used.
Example:
curl --expect100-timeout 2.5 -T file https://example.com
See also --connect-timeout.
--fail-early
Fail and exit on the first detected transfer error.
When curl is used to do multiple transfers on the command line,
it attempts to operate on each given URL, one by one. By de‐
fault, it ignores errors if there are more URLs given and the
last URL's success determines the error code curl returns. So
early failures are "hidden" by subsequent successful transfers.
Using this option, curl instead returns an error on the first
transfer that fails, independent of the amount of URLs that are
given on the command line. This way, no transfer failures go un‐
detected by scripts and similar.
This option does not imply -f, --fail, which causes transfers to
fail due to the server's HTTP status code. You can combine the
two options, however note -f, --fail is not global and is there‐
fore contained by -:, --next.
This option is global and does not need to be specified for each
use of --next.
Providing --fail-early multiple times has no extra effect. Dis‐
able it again with --no-fail-early.
Example:
curl --fail-early https://example.com https://two.example
See also -f, --fail and --fail-with-body. Added in 7.52.0.
--fail-with-body
(HTTP) Return an error on server errors where the HTTP response
code is 400 or greater). In normal cases when an HTTP server
fails to deliver a document, it returns an HTML document stating
so (which often also describes why and more). This flag allows
curl to output and save that content but also to return error
22.
This is an alternative option to -f, --fail which makes curl
fail for the same circumstances but without saving the content.
Providing --fail-with-body multiple times has no extra effect.
Disable it again with --no-fail-with-body.
Example:
curl --fail-with-body https://example.com
See also -f, --fail and --fail-early. This option is mutually
exclusive to -f, --fail. Added in 7.76.0.
-f, --fail
(HTTP) Fail fast with no output at all on server errors. This is
useful to enable scripts and users to better deal with failed
attempts. In normal cases when an HTTP server fails to deliver a
document, it returns an HTML document stating so (which often
also describes why and more). This flag prevents curl from out‐
putting that and return error 22.
This method is not fail-safe and there are occasions where
non-successful response codes slip through, especially when au‐
thentication is involved (response codes 401 and 407).
Providing -f, --fail multiple times has no extra effect. Dis‐
able it again with --no-fail.
Example:
curl --fail https://example.com
See also --fail-with-body and --fail-early. This option is mutu‐
ally exclusive to --fail-with-body.
--false-start
(TLS) Tells curl to use false start during the TLS handshake.
False start is a mode where a TLS client starts sending applica‐
tion data before verifying the server's Finished message, thus
saving a round trip when performing a full handshake.
This is currently only implemented in the Secure Transport (on
iOS 7.0 or later, or OS X 10.9 or later) backend.
Providing --false-start multiple times has no extra effect.
Disable it again with --no-false-start.
Example:
curl --false-start https://example.com
See also --tcp-fastopen.
--form-escape
(HTTP) Tells curl to pass on names of multipart form fields and
files using backslash-escaping instead of percent-encoding.
If --form-escape is provided several times, the last set value
is used.
Example:
curl --form-escape -F 'field\name=curl' -F 'file=@load"this' https://example.com
See also -F, --form. Added in 7.81.0.
--form-string <name=string>
(HTTP SMTP IMAP) Similar to -F, --form except that the value
string for the named parameter is used literally. Leading '@'
and '<' characters, and the ';type=' string in the value have no
special meaning. Use this in preference to -F, --form if there
is any possibility that the string value may accidentally trig‐
ger the '@' or '<' features of -F, --form.
--form-string can be used several times in a command line
Example:
curl --form-string "data" https://example.com
See also -F, --form.
-F, --form <name=content>
(HTTP SMTP IMAP) For HTTP protocol family, this lets curl emu‐
late a filled-in form in which a user has pressed the submit
button. This causes curl to POST data using the Content-Type
multipart/form-data according to RFC 2388.
For SMTP and IMAP protocols, this is the means to compose a mul‐
tipart mail message to transmit.
This enables uploading of binary files etc. To force the 'con‐
tent' part to be a file, prefix the file name with an @ sign. To
just get the content part from a file, prefix the file name with
the symbol <. The difference between @ and < is then that @
makes a file get attached in the post as a file upload, while
the < makes a text field and just get the contents for that text
field from a file.
Tell curl to read content from stdin instead of a file by using
- as filename. This goes for both @ and < constructs. When stdin
is used, the contents is buffered in memory first by curl to de‐
termine its size and allow a possible resend. Defining a part's
data from a named non-regular file (such as a named pipe or sim‐
ilar) is not subject to buffering and is instead read at trans‐
mission time; since the full size is unknown before the transfer
starts, such data is sent as chunks by HTTP and rejected by
IMAP.
Example: send an image to an HTTP server, where 'profile' is the
name of the form-field to which the file portrait.jpg is the in‐
put:
curl -F [email protected] https://example.com/upload.cgi
Example: send your name and shoe size in two text fields to the
server:
curl -F name=John -F shoesize=11 https://example.com/
Example: send your essay in a text field to the server. Send it
as a plain text field, but get the contents for it from a local
file:
curl -F "story=<hugefile.txt" https://example.com/
You can also tell curl what Content-Type to use by using
'type=', in a manner similar to:
curl -F "[email protected];type=text/html" example.com
or
curl -F "name=daniel;type=text/foo" example.com
You can also explicitly change the name field of a file upload
part by setting filename=, like this:
curl -F "file=@localfile;filename=nameinpost" example.com
If filename/path contains ',' or ';', it must be quoted by dou‐
ble-quotes like:
curl -F "file=@\"local,file\";filename=\"name;in;post\"" example.com
or
curl -F 'file=@"local,file";filename="name;in;post"' example.com
Note that if a filename/path is quoted by double-quotes, any
double-quote or backslash within the filename must be escaped by
backslash.
Quoting must also be applied to non-file data if it contains
semicolons, leading/trailing spaces or leading double quotes:
curl -F 'colors="red; green; blue";type=text/x-myapp' example.com
You can add custom headers to the field by setting headers=,
like
curl -F "submit=OK;headers=\"X-submit-type: OK\"" example.com
or
curl -F "submit=OK;headers=@headerfile" example.com
The headers= keyword may appear more that once and above notes
about quoting apply. When headers are read from a file, Empty
lines and lines starting with '#' are comments and ignored; each
header can be folded by splitting between two words and starting
the continuation line with a space; embedded carriage-returns
and trailing spaces are stripped. Here is an example of a
header file contents:
# This file contain two headers.
X-header-1: this is a header
# The following header is folded.
X-header-2: this is
another header
To support sending multipart mail messages, the syntax is ex‐
tended as follows:
- name can be omitted: the equal sign is the first character of
the argument,
- if data starts with '(', this signals to start a new multi‐
part: it can be followed by a content type specification.
- a multipart can be terminated with a '=)' argument.
Example: the following command sends an SMTP mime email consist‐
ing in an inline part in two alternative formats: plain text and
HTML. It attaches a text file:
curl -F '=(;type=multipart/alternative' \
-F '=plain text message' \
-F '= <body>HTML message</body>;type=text/html' \
-F '=)' -F '[email protected]' ... smtp://example.com
Data can be encoded for transfer using encoder=. Available en‐
codings are binary and 8bit that do nothing else than adding the
corresponding Content-Transfer-Encoding header, 7bit that only
rejects 8-bit characters with a transfer error, quoted-printable
and base64 that encodes data according to the corresponding
schemes, limiting lines length to 76 characters.
Example: send multipart mail with a quoted-printable text mes‐
sage and a base64 attached file:
curl -F '=text message;encoder=quoted-printable' \
-F '=@localfile;encoder=base64' ... smtp://example.com
See further examples and details in the MANUAL.
-F, --form can be used several times in a command line
Example:
curl --form "name=curl" --form "file=@loadthis" https://example.com
See also -d, --data, --form-string and --form-escape. This op‐
tion is mutually exclusive to -d, --data and -I, --head and -T,
--upload-file.
--ftp-account <data>
(FTP) When an FTP server asks for "account data" after user name
and password has been provided, this data is sent off using the
ACCT command.
If --ftp-account is provided several times, the last set value
is used.
Example:
curl --ftp-account "mr.robot" ftp://example.com/
See also -u, --user.
--ftp-alternative-to-user <command>
(FTP) If authenticating with the USER and PASS commands fails,
send this command. When connecting to Tumbleweed's Secure
Transport server over FTPS using a client certificate, using
"SITE AUTH" tells the server to retrieve the username from the
certificate.
If --ftp-alternative-to-user is provided several times, the last
set value is used.
Example:
curl --ftp-alternative-to-user "U53r" ftp://example.com
See also --ftp-account and -u, --user.
--ftp-create-dirs
(FTP SFTP) When an FTP or SFTP URL/operation uses a path that
does not currently exist on the server, the standard behavior of
curl is to fail. Using this option, curl instead attempts to
create missing directories.
Providing --ftp-create-dirs multiple times has no extra effect.
Disable it again with --no-ftp-create-dirs.
Example:
curl --ftp-create-dirs -T file ftp://example.com/remote/path/file
See also --create-dirs.
--ftp-method <method>
(FTP) Control what method curl should use to reach a file on an
FTP(S) server. The method argument should be one of the follow‐
ing alternatives:
multicwd
curl does a single CWD operation for each path part in
the given URL. For deep hierarchies this means many com‐
mands. This is how RFC 1738 says it should be done. This
is the default but the slowest behavior.
nocwd curl does no CWD at all. curl does SIZE, RETR, STOR etc
and give a full path to the server for all these com‐
mands. This is the fastest behavior.
singlecwd
curl does one CWD with the full target directory and then
operates on the file "normally" (like in the multicwd
case). This is somewhat more standards compliant than
'nocwd' but without the full penalty of 'multicwd'.
If --ftp-method is provided several times, the last set value is
used.
Examples:
curl --ftp-method multicwd ftp://example.com/dir1/dir2/file
curl --ftp-method nocwd ftp://example.com/dir1/dir2/file
curl --ftp-method singlecwd ftp://example.com/dir1/dir2/file
See also -l, --list-only.
--ftp-pasv
(FTP) Use passive mode for the data connection. Passive is the
internal default behavior, but using this option can be used to
override a previous -P, --ftp-port option.
Reversing an enforced passive really is not doable but you must
then instead enforce the correct -P, --ftp-port again.
Passive mode means that curl tries the EPSV command first and
then PASV, unless --disable-epsv is used.
Providing --ftp-pasv multiple times has no extra effect. Dis‐
able it again with --no-ftp-pasv.
Example:
curl --ftp-pasv ftp://example.com/
See also --disable-epsv.
-P, --ftp-port <address>
(FTP) Reverses the default initiator/listener roles when con‐
necting with FTP. This option makes curl use active mode. curl
then tells the server to connect back to the client's specified
address and port, while passive mode asks the server to setup an
IP address and port for it to connect to. <address> should be
one of:
interface
e.g. "eth0" to specify which interface's IP address you
want to use (Unix only)
IP address
e.g. "192.168.10.1" to specify the exact IP address
host name
e.g. "my.host.domain" to specify the machine
- make curl pick the same IP address that is already used
for the control connection
Disable the use of PORT with --ftp-pasv. Disable the attempt to
use the EPRT command instead of PORT by using --disable-eprt.
EPRT is really PORT++.
You can also append ":[start]-[end]" to the right of the ad‐
dress, to tell curl what TCP port range to use. That means you
specify a port range, from a lower to a higher number. A single
number works as well, but do note that it increases the risk of
failure since the port may not be available.
If -P, --ftp-port is provided several times, the last set value
is used.
Examples:
curl -P - ftp:/example.com
curl -P eth0 ftp:/example.com
curl -P 192.168.0.2 ftp:/example.com
See also --ftp-pasv and --disable-eprt.
--ftp-pret
(FTP) Tell curl to send a PRET command before PASV (and EPSV).
Certain FTP servers, mainly drftpd, require this non-standard
command for directory listings as well as up and downloads in
PASV mode.
Providing --ftp-pret multiple times has no extra effect. Dis‐
able it again with --no-ftp-pret.
Example:
curl --ftp-pret ftp://example.com/
See also -P, --ftp-port and --ftp-pasv.
--ftp-skip-pasv-ip
(FTP) Tell curl to not use the IP address the server suggests in
its response to curl's PASV command when curl connects the data
connection. Instead curl reuses the same IP address it already
uses for the control connection.
This option is enabled by default (added in 7.74.0).
This option has no effect if PORT, EPRT or EPSV is used instead
of PASV.
Providing --ftp-skip-pasv-ip multiple times has no extra effect.
Disable it again with --no-ftp-skip-pasv-ip.
Example:
curl --ftp-skip-pasv-ip ftp://example.com/
See also --ftp-pasv.
--ftp-ssl-ccc-mode <active/passive>
(FTP) Sets the CCC mode. The passive mode does not initiate the
shutdown, but instead waits for the server to do it, and does
not reply to the shutdown from the server. The active mode ini‐
tiates the shutdown and waits for a reply from the server.
Providing --ftp-ssl-ccc-mode multiple times has no extra effect.
Disable it again with --no-ftp-ssl-ccc-mode.
Example:
curl --ftp-ssl-ccc-mode active --ftp-ssl-ccc ftps://example.com/
See also --ftp-ssl-ccc.
--ftp-ssl-ccc
(FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS
layer after authenticating. The rest of the control channel com‐
munication is be unencrypted. This allows NAT routers to follow
the FTP transaction. The default mode is passive.
Providing --ftp-ssl-ccc multiple times has no extra effect.
Disable it again with --no-ftp-ssl-ccc.
Example:
curl --ftp-ssl-ccc ftps://example.com/
See also --ssl and --ftp-ssl-ccc-mode.
--ftp-ssl-control
(FTP) Require SSL/TLS for the FTP login, clear for transfer.
Allows secure authentication, but non-encrypted data transfers
for efficiency. Fails the transfer if the server does not sup‐
port SSL/TLS.
Providing --ftp-ssl-control multiple times has no extra effect.
Disable it again with --no-ftp-ssl-control.
Example:
curl --ftp-ssl-control ftp://example.com
See also --ssl.
-G, --get
When used, this option makes all data specified with -d, --data,
--data-binary or --data-urlencode to be used in an HTTP GET re‐
quest instead of the POST request that otherwise would be used.
The data is appended to the URL with a '?' separator.
If used in combination with -I, --head, the POST data is instead
appended to the URL with a HEAD request.
Providing -G, --get multiple times has no extra effect. Disable
it again with --no-get.
Examples:
curl --get https://example.com
curl --get -d "tool=curl" -d "age=old" https://example.com
curl --get -I -d "tool=curl" https://example.com
See also -d, --data and -X, --request.
-g, --globoff
This option switches off the "URL globbing parser". When you set
this option, you can specify URLs that contain the letters {}[]
without having curl itself interpret them. Note that these let‐
ters are not normal legal URL contents but they should be en‐
coded according to the URI standard.
Providing -g, --globoff multiple times has no extra effect.
Disable it again with --no-globoff.
Example:
curl -g "https://example.com/{[]}}}}"
See also -K, --config and -q, --disable.
--happy-eyeballs-timeout-ms <milliseconds>
Happy Eyeballs is an algorithm that attempts to connect to both
IPv4 and IPv6 addresses for dual-stack hosts, giving IPv6 a
head-start of the specified number of milliseconds. If the IPv6
address cannot be connected to within that time, then a connec‐
tion attempt is made to the IPv4 address in parallel. The first
connection to be established is the one that is used.
The range of suggested useful values is limited. Happy Eyeballs
RFC 6555 says "It is RECOMMENDED that connection attempts be
paced 150-250 ms apart to balance human factors against network
load." libcurl currently defaults to 200 ms. Firefox and Chrome
currently default to 300 ms.
If --happy-eyeballs-timeout-ms is provided several times, the
last set value is used.
Example:
curl --happy-eyeballs-timeout-ms 500 https://example.com
See also -m, --max-time and --connect-timeout. Added in 7.59.0.
--haproxy-clientip
(HTTP) Sets a client IP in HAProxy PROXY protocol v1 header at
the beginning of the connection.
For valid requests, IPv4 addresses must be indicated as a series
of exactly 4 integers in the range [0..255] inclusive written in
decimal representation separated by exactly one dot between each
other. Heading zeroes are not permitted in front of numbers in
order to avoid any possible confusion with octal numbers. IPv6
addresses must be indicated as series of 4 hexadecimal digits
(upper or lower case) delimited by colons between each other,
with the acceptance of one double colon sequence to replace the
largest acceptable range of consecutive zeroes. The total number
of decoded bits must exactly be 128.
Otherwise, any string can be accepted for the client IP and get
sent.
It replaces --haproxy-protocol if used, it is not necessary to
specify both flags.
This option is primarily useful when sending test requests to
verify a service is working as intended.
If --haproxy-clientip is provided several times, the last set
value is used.
Example:
curl --haproxy-clientip $IP
See also -x, --proxy. Added in 8.2.0.
--haproxy-protocol
(HTTP) Send a HAProxy PROXY protocol v1 header at the beginning
of the connection. This is used by some load balancers and re‐
verse proxies to indicate the client's true IP address and port.
This option is primarily useful when sending test requests to a
service that expects this header.
Providing --haproxy-protocol multiple times has no extra effect.
Disable it again with --no-haproxy-protocol.
Example:
curl --haproxy-protocol https://example.com
See also -x, --proxy. Added in 7.60.0.
-I, --head
(HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the
command HEAD which this uses to get nothing but the header of a
document. When used on an FTP or FILE file, curl displays the
file size and last modification time only.
Providing -I, --head multiple times has no extra effect. Dis‐
able it again with --no-head.
Example:
curl -I https://example.com
See also -G, --get, -v, --verbose and --trace-ascii.
-H, --header <header/@file>
(HTTP IMAP SMTP) Extra header to include in information sent.
When used within an HTTP request, it is added to the regular re‐
quest headers.
For an IMAP or SMTP MIME uploaded mail built with -F, --form op‐
tions, it is prepended to the resulting MIME document, effec‐
tively including it at the mail global level. It does not affect
raw uploaded mails (Added in 7.56.0).
You may specify any number of extra headers. Note that if you
should add a custom header that has the same name as one of the
internal ones curl would use, your externally set header is used
instead of the internal one. This allows you to make even trick‐
ier stuff than curl would normally do. You should not replace
internally set headers without knowing perfectly well what you
are doing. Remove an internal header by giving a replacement
without content on the right side of the colon, as in: -H
"Host:". If you send the custom header with no-value then its
header must be terminated with a semicolon, such as -H "X-Cus‐
tom-Header;" to send "X-Custom-Header:".
curl makes sure that each header you add/replace is sent with
the proper end-of-line marker, you should thus not add that as a
part of the header content: do not add newlines or carriage re‐
turns, they only mess things up for you. curl passes on the ver‐
batim string you give it without any filter or other safe
guards. That includes white space and control characters.
This option can take an argument in @filename style, which then
adds a header for each line in the input file. Using @- makes
curl read the header file from stdin. Added in 7.55.0.
Please note that most anti-spam utilities check the presence and
value of several MIME mail headers: these are "From:", "To:",
"Date:" and "Subject:" among others and should be added with
this option.
You need --proxy-header to send custom headers intended for an
HTTP proxy. Added in 7.37.0.
Passing on a "Transfer-Encoding: chunked" header when doing an
HTTP request with a request body, makes curl send the data using
chunked encoding.
WARNING: headers set with this option are set in all HTTP re‐
quests - even after redirects are followed, like when told with
-L, --location. This can lead to the header being sent to other
hosts than the original host, so sensitive headers should be
used with caution combined with following redirects.
-H, --header can be used several times in a command line
Examples:
curl -H "X-First-Name: Joe" https://example.com
curl -H "User-Agent: yes-please/2000" https://example.com
curl -H "Host:" https://example.com
curl -H @headers.txt https://example.com
See also -A, --user-agent and -e, --referer.
-h, --help <category>
Usage help. This lists all curl command line options within the
given category.
If no argument is provided, curl displays only the most impor‐
tant command line arguments.
For category all, curl displays help for all options.
If category is specified, curl displays all available help cate‐
gories.
Example:
curl --help all
See also -v, --verbose.
--hostpubmd5 <md5>
(SFTP SCP) Pass a string containing 32 hexadecimal digits. The
string should be the 128 bit MD5 checksum of the remote host's
public key, curl refuses the connection with the host unless the
md5sums match.
If --hostpubmd5 is provided several times, the last set value is
used.
Example:
curl --hostpubmd5 e5c1c49020640a5ab0f2034854c321a8 sftp://example.com/
See also --hostpubsha256.
--hostpubsha256 <sha256>
(SFTP SCP) Pass a string containing a Base64-encoded SHA256 hash
of the remote host's public key. Curl refuses the connection
with the host unless the hashes match.
This feature requires libcurl to be built with libssh2 and does
not work with other SSH backends.
If --hostpubsha256 is provided several times, the last set value
is used.
Example:
curl --hostpubsha256 NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ= sftp://example.com/
See also --hostpubmd5. Added in 7.80.0.
--hsts <file name>
(HTTPS) This option enables HSTS for the transfer. If the file
name points to an existing HSTS cache file, that is used. After
a completed transfer, the cache is saved to the file name again
if it has been modified.
If curl is told to use HTTP:// for a transfer involving a host
name that exists in the HSTS cache, it upgrades the transfer to
use HTTPS. Each HSTS cache entry has an individual life time af‐
ter which the upgrade is no longer performed.
Specify a "" file name (zero length) to avoid loading/saving and
make curl just handle HSTS in memory.
If this option is used several times, curl loads contents from
all the files but the last one is used for saving.
--hsts can be used several times in a command line
Example:
curl --hsts cache.txt https://example.com
See also --proto. Added in 7.74.0.
--http0.9
(HTTP) Tells curl to be fine with HTTP version 0.9 response.
HTTP/0.9 is a response without headers and therefore you can
also connect with this to non-HTTP servers and still get a re‐
sponse since curl simply transparently downgrades - if allowed.
HTTP/0.9 is disabled by default (added in 7.66.0)
Providing --http0.9 multiple times has no extra effect. Disable
it again with --no-http0.9.
Example:
curl --http0.9 https://example.com
See also --http1.1, --http2 and --http3. Added in 7.64.0.
-0, --http1.0
(HTTP) Tells curl to use HTTP version 1.0 instead of using its
internally preferred HTTP version.
Providing -0, --http1.0 multiple times has no extra effect.
Example:
curl --http1.0 https://example.com
See also --http0.9 and --http1.1. This option is mutually exclu‐
sive to --http1.1 and --http2 and --http2-prior-knowledge and
--http3.
--http1.1
(HTTP) Tells curl to use HTTP version 1.1.
Providing --http1.1 multiple times has no extra effect.
Example:
curl --http1.1 https://example.com
See also -0, --http1.0 and --http0.9. This option is mutually
exclusive to -0, --http1.0 and --http2 and --http2-prior-knowl‐
edge and --http3.
--http2-prior-knowledge
(HTTP) Tells curl to issue its non-TLS HTTP requests using
HTTP/2 without HTTP/1.1 Upgrade. It requires prior knowledge
that the server supports HTTP/2 straight away. HTTPS requests
still do HTTP/2 the standard way with negotiated protocol ver‐
sion in the TLS handshake.
Providing --http2-prior-knowledge multiple times has no extra
effect. Disable it again with --no-http2-prior-knowledge.
Example:
curl --http2-prior-knowledge https://example.com
See also --http2 and --http3. --http2-prior-knowledge requires
that the underlying libcurl was built to support HTTP/2. This
option is mutually exclusive to --http1.1 and -0, --http1.0 and
--http2 and --http3.
--http2
(HTTP) Tells curl to use HTTP version 2.
For HTTPS, this means curl negotiates HTTP/2 in the TLS hand‐
shake. curl does this by default.
For HTTP, this means curl attempts to upgrade the request to
HTTP/2 using the Upgrade: request header.
When curl uses HTTP/2 over HTTPS, it does not itself insist on
TLS 1.2 or higher even though that is required by the specifica‐
tion. A user can add this version requirement with --tlsv1.2.
Providing --http2 multiple times has no extra effect.
Example:
curl --http2 https://example.com
See also --http1.1, --http3 and --no-alpn. --http2 requires that
the underlying libcurl was built to support HTTP/2. This option
is mutually exclusive to --http1.1 and -0, --http1.0 and
--http2-prior-knowledge and --http3.
--http3-only
(HTTP) **WARNING**: this option is experimental. Do not use in
production.
Instructs curl to use HTTP/3 to the host in the URL, with no
fallback to earlier HTTP versions. HTTP/3 can only be used for
HTTPS and not for HTTP URLs. For HTTP, this option triggers an
error.
This option allows a user to avoid using the Alt-Svc method of
upgrading to HTTP/3 when you know that the target speaks HTTP/3
on the given host and port.
This option makes curl fail if a QUIC connection cannot be es‐
tablished, it does not attempt any other HTTP versions on its
own. Use --http3 for similar functionality with a fallback.
Providing --http3-only multiple times has no extra effect.
Example:
curl --http3-only https://example.com
See also --http1.1, --http2 and --http3. --http3-only requires
that the underlying libcurl was built to support HTTP/3. This
option is mutually exclusive to --http1.1 and -0, --http1.0 and
--http2 and --http2-prior-knowledge and --http3. Added in
7.88.0.
--http3
(HTTP) **WARNING**: this option is experimental. Do not use in
production.
Tells curl to try HTTP/3 to the host in the URL, but fallback to
earlier HTTP versions if the HTTP/3 connection establishment
fails. HTTP/3 is only available for HTTPS and not for HTTP URLs.
This option allows a user to avoid using the Alt-Svc method of
upgrading to HTTP/3 when you know that the target speaks HTTP/3
on the given host and port.
When asked to use HTTP/3, curl issues a separate attempt to use
older HTTP versions with a slight delay, so if the HTTP/3 trans‐
fer fails or is slow, curl still tries to proceed with an older
HTTP version.
Use --http3-only for similar functionality without a fallback.
Providing --http3 multiple times has no extra effect.
Example:
curl --http3 https://example.com
See also --http1.1 and --http2. --http3 requires that the under‐
lying libcurl was built to support HTTP/3. This option is mutu‐
ally exclusive to --http1.1 and -0, --http1.0 and --http2 and
--http2-prior-knowledge and --http3-only. Added in 7.66.0.
--ignore-content-length
(FTP HTTP) For HTTP, Ignore the Content-Length header. This is
particularly useful for servers running Apache 1.x, which re‐
ports incorrect Content-Length for files larger than 2 giga‐
bytes.
For FTP, this makes curl skip the SIZE command to figure out the
size before downloading a file.
This option does not work for HTTP if libcurl was built to use
hyper.
Providing --ignore-content-length multiple times has no extra
effect. Disable it again with --no-ignore-content-length.
Example:
curl --ignore-content-length https://example.com
See also --ftp-skip-pasv-ip.
-i, --include
Include the HTTP response headers in the output. The HTTP re‐
sponse headers can include things like server name, cookies,
date of the document, HTTP version and more...
To view the request headers, consider the -v, --verbose option.
Prior to 7.75.0 curl did not print the headers if -f, --fail was
used in combination with this option and there was error re‐
ported by server.
Providing -i, --include multiple times has no extra effect.
Disable it again with --no-include.
Example:
curl -i https://example.com
See also -v, --verbose.
-k, --insecure
(TLS SFTP SCP) By default, every secure connection curl makes is
verified to be secure before the transfer takes place. This op‐
tion makes curl skip the verification step and proceed without
checking.
When this option is not used for protocols using TLS, curl veri‐
fies the server's TLS certificate before it continues: that the
certificate contains the right name which matches the host name
used in the URL and that the certificate has been signed by a CA
certificate present in the cert store. See this online resource
for further details:
https://curl.se/docs/sslcerts.html
For SFTP and SCP, this option makes curl skip the known_hosts
verification. known_hosts is a file normally stored in the
user's home directory in the ".ssh" subdirectory, which contains
host names and their public keys.
WARNING: using this option makes the transfer insecure.
When curl uses secure protocols it trusts responses and allows
for example HSTS and Alt-Svc information to be stored and used
subsequently. Using -k, --insecure can make curl trust and use
such information from malicious servers.
Providing -k, --insecure multiple times has no extra effect.
Disable it again with --no-insecure.
Example:
curl --insecure https://example.com
See also --proxy-insecure, --cacert and --capath.
--interface <name>
Perform an operation using a specified interface. You can enter
interface name, IP address or host name. An example could look
like:
curl --interface eth0:1 https://www.example.com/
On Linux it can be used to specify a VRF, but the binary needs
to either have CAP_NET_RAW or to be run as root. More informa‐
tion about Linux VRF: https://www.kernel.org/doc/Documenta‐
tion/networking/vrf.txt
If --interface is provided several times, the last set value is
used.
Example:
curl --interface eth0 https://example.com
See also --dns-interface.
--ipfs-gateway <URL>
Specify which gateway to use for IPFS and IPNS URLs. Not speci‐
fying this will instead make curl check if the IPFS_GATEWAY en‐
vironment variable is set, or if a ~/.ipfs/gateway file holding
the gateway URL exists.
If you run a local IPFS node, this gateway is by default avail‐
able under http://localhost:8080. A full example URL would look
like:
curl --ipfs-gateway http://localhost:8080 ipfs://bafybeigagd5nmnn2iys2f3doro7ydrevyr2mzarwidgadawmamiteydbzi
There are many public IPFS gateways. See for example:
https://ipfs.github.io/public-gateway-checker/
WARNING: If you opt to go for a remote gateway you should be
aware that you completely trust the gateway. This is fine in lo‐
cal gateways as you host it yourself. With remote gateways there
could potentially be a malicious actor returning you data that
does not match the request you made, inspect or even interfere
with the request. You will not notice this when using curl. A
mitigation could be to go for a "trustless" gateway. This means
you locally verify that the data. Consult the docs page on
trusted vs trustless: https://docs.ipfs.tech/refer‐
ence/http/gateway/#trusted-vs-trustless
If --ipfs-gateway is provided several times, the last set value
is used.
Example:
curl --ipfs-gateway https://example.com ipfs://
See also -h, --help and -M, --manual. Added in 8.4.0.
-4, --ipv4
This option tells curl to use IPv4 addresses only when resolving
host names, and not for example try IPv6.
Providing -4, --ipv4 multiple times has no extra effect.
Example:
curl --ipv4 https://example.com
See also --http1.1 and --http2. This option is mutually exclu‐
sive to -6, --ipv6.
-6, --ipv6
This option tells curl to use IPv6 addresses only when resolving
host names, and not for example try IPv4.
Providing -6, --ipv6 multiple times has no extra effect.
Example:
curl --ipv6 https://example.com
See also --http1.1 and --http2. This option is mutually exclu‐
sive to -4, --ipv4.
--json <data>
(HTTP) Sends the specified JSON data in a POST request to the
HTTP server. --json works as a shortcut for passing on these
three options:
--data [arg]
--header "Content-Type: application/json"
--header "Accept: application/json"
There is no verification that the passed in data is actual JSON
or that the syntax is correct.
If you start the data with the letter @, the rest should be a
file name to read the data from, or a single dash (-) if you
want curl to read the data from stdin. Posting data from a file
named 'foobar' would thus be done with --json @foobar and to in‐
stead read the data from stdin, use --json @-.
If this option is used more than once on the same command line,
the additional data pieces are concatenated to the previous be‐
fore sending.
The headers this option sets can be overridden with -H, --header
as usual.
--json can be used several times in a command line
Examples:
curl --json '{ "drink": "coffe" }' https://example.com
curl --json '{ "drink":' --json ' "coffe" }' https://example.com
curl --json @prepared https://example.com
curl --json @- https://example.com < json.txt
See also --data-binary and --data-raw. This option is mutually
exclusive to -F, --form and -I, --head and -T, --upload-file.
Added in 7.82.0.
-j, --junk-session-cookies
(HTTP) When curl is told to read cookies from a given file, this
option makes it discard all "session cookies". This has the same
effect as if a new session is started. Typical browsers discard
session cookies when they are closed down.
Providing -j, --junk-session-cookies multiple times has no extra
effect. Disable it again with --no-junk-session-cookies.
Example:
curl --junk-session-cookies -b cookies.txt https://example.com
See also -b, --cookie and -c, --cookie-jar.
--keepalive-time <seconds>
This option sets the time a connection needs to remain idle be‐
fore sending keepalive probes and the time between individual
keepalive probes. It is currently effective on operating systems
offering the TCP_KEEPIDLE and TCP_KEEPINTVL socket options
(meaning Linux, recent AIX, HP-UX and more). Keepalives are
used by the TCP stack to detect broken networks on idle connec‐
tions. The number of missed keepalive probes before declaring
the connection down is OS dependent and is commonly 9 or 10.
This option has no effect if --no-keepalive is used.
If unspecified, the option defaults to 60 seconds.
If --keepalive-time is provided several times, the last set
value is used.
Example:
curl --keepalive-time 20 https://example.com
See also --no-keepalive and -m, --max-time.
--key-type <type>
(TLS) Private key file type. Specify which type your --key pro‐
vided private key is. DER, PEM, and ENG are supported. If not
specified, PEM is assumed.
If --key-type is provided several times, the last set value is
used.
Example:
curl --key-type DER --key here https://example.com
See also --key.
--key <key>
(TLS SSH) Private key file name. Allows you to provide your pri‐
vate key in this separate file. For SSH, if not specified, curl
tries the following candidates in order: '~/.ssh/id_rsa',
'~/.ssh/id_dsa', './id_rsa', './id_dsa'.
If curl is built against OpenSSL library, and the engine pkcs11
is available, then a PKCS#11 URI (RFC 7512) can be used to spec‐
ify a private key located in a PKCS#11 device. A string begin‐
ning with "pkcs11:" is interpreted as a PKCS#11 URI. If a
PKCS#11 URI is provided, then the --engine option is set as
"pkcs11" if none was provided and the --key-type option is set
as "ENG" if none was provided.
If curl is built against Secure Transport or Schannel then this
option is ignored for TLS protocols (HTTPS, etc). Those backends
expect the private key to be already present in the keychain or
PKCS#12 file containing the certificate.
If --key is provided several times, the last set value is used.
Example:
curl --cert certificate --key here https://example.com
See also --key-type and -E, --cert.
--krb <level>
(FTP) Enable Kerberos authentication and use. The level must be
entered and should be one of 'clear', 'safe', 'confidential', or
'private'. Should you use a level that is not one of these,
'private' is used.
If --krb is provided several times, the last set value is used.
Example:
curl --krb clear ftp://example.com/
See also --delegation and --ssl. --krb requires that the under‐
lying libcurl was built to support Kerberos.
--libcurl <file>
Append this option to any ordinary curl command line, and you
get libcurl-using C source code written to the file that does
the equivalent of what your command-line operation does!
This option is global and does not need to be specified for each
use of --next.
If --libcurl is provided several times, the last set value is
used.
Example:
curl --libcurl client.c https://example.com
See also -v, --verbose.
--limit-rate <speed>
Specify the maximum transfer rate you want curl to use - for
both downloads and uploads. This feature is useful if you have a
limited pipe and you would like your transfer not to use your
entire bandwidth. To make it slower than it otherwise would be.
The given speed is measured in bytes/second, unless a suffix is
appended. Appending 'k' or 'K' counts the number as kilobytes,
'm' or 'M' makes it megabytes, while 'g' or 'G' makes it giga‐
bytes. The suffixes (k, M, G, T, P) are 1024 based. For example
1k is 1024. Examples: 200K, 3m and 1G.
The rate limiting logic works on averaging the transfer speed to
no more than the set threshold over a period of multiple sec‐
onds.
If you also use the -Y, --speed-limit option, that option takes
precedence and might cripple the rate-limiting slightly, to help
keeping the speed-limit logic working.
If --limit-rate is provided several times, the last set value is
used.
Examples:
curl --limit-rate 100K https://example.com
curl --limit-rate 1000 https://example.com
curl --limit-rate 10M https://example.com
See also --rate, -Y, --speed-limit and -y, --speed-time.
-l, --list-only
(FTP POP3 SFTP) (FTP) When listing an FTP directory, this switch
forces a name-only view. This is especially useful if the user
wants to machine-parse the contents of an FTP directory since
the normal directory view does not use a standard look or for‐
mat. When used like this, the option causes an NLST command to
be sent to the server instead of LIST.
Note: Some FTP servers list only files in their response to
NLST; they do not include sub-directories and symbolic links.
(SFTP) When listing an SFTP directory, this switch forces a
name-only view, one per line. This is especially useful if the
user wants to machine-parse the contents of an SFTP directory
since the normal directory view provides more information than
just file names.
(POP3) When retrieving a specific email from POP3, this switch
forces a LIST command to be performed instead of RETR. This is
particularly useful if the user wants to see if a specific mes‐
sage-id exists on the server and what size it is.
Note: When combined with -X, --request, this option can be used
to send a UIDL command instead, so the user may use the email's
unique identifier rather than its message-id to make the re‐
quest.
Providing -l, --list-only multiple times has no extra effect.
Disable it again with --no-list-only.
Example:
curl --list-only ftp://example.com/dir/
See also -Q, --quote and -X, --request.
--local-port <num/range>
Set a preferred single number or range (FROM-TO) of local port
numbers to use for the connection(s). Note that port numbers by
nature are a scarce resource so setting this range to something
too narrow might cause unnecessary connection setup failures.
If --local-port is provided several times, the last set value is
used.
Example:
curl --local-port 1000-3000 https://example.com
See also -g, --globoff.
--location-trusted
(HTTP) Like -L, --location, but allows sending the name + pass‐
word to all hosts that the site may redirect to. This may or may
not introduce a security breach if the site redirects you to a
site to which you send your authentication info (which is plain‐
text in the case of HTTP Basic authentication).
Providing --location-trusted multiple times has no extra effect.
Disable it again with --no-location-trusted.
Example:
curl --location-trusted -u user:password https://example.com
See also -u, --user.
-L, --location
(HTTP) If the server reports that the requested page has moved
to a different location (indicated with a Location: header and a
3XX response code), this option makes curl redo the request on
the new place. If used together with -i, --include or -I,
--head, headers from all requested pages are shown.
When authentication is used, curl only sends its credentials to
the initial host. If a redirect takes curl to a different host,
it does not get the user+password pass on. See also --loca‐
tion-trusted on how to change this.
Limit the amount of redirects to follow by using the
--max-redirs option.
When curl follows a redirect and if the request is a POST, it
sends the following request with a GET if the HTTP response was
301, 302, or 303. If the response code was any other 3xx code,
curl resends the following request using the same unmodified
method.
You can tell curl to not change POST requests to GET after a 30x
response by using the dedicated options for that: --post301,
--post302 and --post303.
The method set with -X, --request overrides the method curl
would otherwise select to use.
Providing -L, --location multiple times has no extra effect.
Disable it again with --no-location.
Example:
curl -L https://example.com
See also --resolve and --alt-svc.
--login-options <options>
(IMAP LDAP POP3 SMTP) Specify the login options to use during
server authentication.
You can use login options to specify protocol specific options
that may be used during authentication. At present only IMAP,
POP3 and SMTP support login options. For more information about
login options please see RFC 2384, RFC 5092 and the IETF draft
https://datatracker.ietf.org/doc/html/draft-earhart-url-smtp-00.
Since 8.2.0, IMAP supports the login option "AUTH=+LOGIN". With
this option, curl uses the plain (not SASL) LOGIN IMAP command
even if the server advertises SASL authentication. Care should
be taken in using this option, as it sends your password over
the network in plain text. This does not work if the IMAP server
disables the plain LOGIN (e.g. to prevent password snooping).
If --login-options is provided several times, the last set value
is used.
Example:
curl --login-options 'AUTH=*' imap://example.com
See also -u, --user.
--mail-auth <address>
(SMTP) Specify a single address. This is used to specify the au‐
thentication address (identity) of a submitted message that is
being relayed to another server.
If --mail-auth is provided several times, the last set value is
used.
Example:
curl --mail-auth [email protected] -T mail smtp://example.com/
See also --mail-rcpt and --mail-from.
--mail-from <address>
(SMTP) Specify a single address that the given mail should get
sent from.
If --mail-from is provided several times, the last set value is
used.
Example:
curl --mail-from [email protected] -T mail smtp://example.com/
See also --mail-rcpt and --mail-auth.
--mail-rcpt-allowfails
(SMTP) When sending data to multiple recipients, by default curl
aborts SMTP conversation if at least one of the recipients
causes RCPT TO command to return an error.
The default behavior can be changed by passing --mail-rcpt-al‐
lowfails command-line option which makes curl ignore errors and
proceed with the remaining valid recipients.
If all recipients trigger RCPT TO failures and this flag is
specified, curl still aborts the SMTP conversation and returns
the error received from to the last RCPT TO command.
Providing --mail-rcpt-allowfails multiple times has no extra ef‐
fect. Disable it again with --no-mail-rcpt-allowfails.
Example:
curl --mail-rcpt-allowfails --mail-rcpt [email protected] smtp://example.com
See also --mail-rcpt. Added in 7.69.0.
--mail-rcpt <address>
(SMTP) Specify a single email address, user name or mailing list
name. Repeat this option several times to send to multiple re‐
cipients.
When performing an address verification (VRFY command), the re‐
cipient should be specified as the user name or user name and
domain (as per Section 3.5 of RFC 5321).
When performing a mailing list expand (EXPN command), the recip‐
ient should be specified using the mailing list name, such as
"Friends" or "London-Office".
--mail-rcpt can be used several times in a command line
Example:
curl --mail-rcpt [email protected] smtp://example.com
See also --mail-rcpt-allowfails.
-M, --manual
Manual. Display the huge help text.
Example:
curl --manual
See also -v, --verbose, --libcurl and --trace.
--max-filesize <bytes>
(FTP HTTP MQTT) Specify the maximum size (in bytes) of a file to
download. If the file requested is larger than this value, the
transfer does not start and curl returns with exit code 63.
A size modifier may be used. For example, Appending 'k' or 'K'
counts the number as kilobytes, 'm' or 'M' makes it megabytes,
while 'g' or 'G' makes it gigabytes. Examples: 200K, 3m and 1G.
(Added in 7.58.0)
NOTE: before curl 8.4.0, when the file size is not known prior
to download, for such files this option has no effect even if
the file transfer ends up being larger than this given limit.
Starting with curl 8.4.0, this option aborts the transfer if it
reaches the threshold during transfer.
If --max-filesize is provided several times, the last set value
is used.
Example:
curl --max-filesize 100K https://example.com
See also --limit-rate.
--max-redirs <num>
(HTTP) Set maximum number of redirections to follow. When -L,
--location is used, to prevent curl from following too many
redirects, by default, the limit is set to 50 redirects. Set
this option to -1 to make it unlimited.
If --max-redirs is provided several times, the last set value is
used.
Example:
curl --max-redirs 3 --location https://example.com
See also -L, --location.
-m, --max-time <fractional seconds>
Maximum time in seconds that you allow each transfer to take.
This is useful for preventing your batch jobs from hanging for
hours due to slow networks or links going down. This option ac‐
cepts decimal values.
If you enable retrying the transfer (--retry) then the maximum
time counter is reset each time the transfer is retried. You can
use --retry-max-time to limit the retry time.
The decimal value needs to provided using a dot (.) as decimal
separator - not the local version even if it might be using an‐
other separator.
If -m, --max-time is provided several times, the last set value
is used.
Examples:
curl --max-time 10 https://example.com
curl --max-time 2.92 https://example.com
See also --connect-timeout and --retry-max-time.
--metalink
This option was previously used to specify a Metalink resource.
Metalink support is disabled in curl for security reasons (added
in 7.78.0).
If --metalink is provided several times, the last set value is
used.
Example:
curl --metalink file https://example.com
See also -Z, --parallel.
--negotiate
(HTTP) Enables Negotiate (SPNEGO) authentication.
This option requires a library built with GSS-API or SSPI sup‐
port. Use -V, --version to see if your curl supports
GSS-API/SSPI or SPNEGO.
When using this option, you must also provide a fake -u, --user
option to activate the authentication code properly. Sending a
'-u :' is enough as the user name and password from the -u,
--user option are not actually used.
Providing --negotiate multiple times has no extra effect.
Example:
curl --negotiate -u : https://example.com
See also --basic, --ntlm, --anyauth and --proxy-negotiate.
--netrc-file <filename>
This option is similar to -n, --netrc, except that you provide
the path (absolute or relative) to the netrc file that curl
should use. You can only specify one netrc file per invocation.
It abides by --netrc-optional if specified.
If --netrc-file is provided several times, the last set value is
used.
Example:
curl --netrc-file netrc https://example.com
See also -n, --netrc, -u, --user and -K, --config. This option
is mutually exclusive to -n, --netrc.
--netrc-optional
Similar to -n, --netrc, but this option makes the .netrc usage
optional and not mandatory as the -n, --netrc option does.
Providing --netrc-optional multiple times has no extra effect.
Disable it again with --no-netrc-optional.
Example:
curl --netrc-optional https://example.com
See also --netrc-file. This option is mutually exclusive to -n,
--netrc.
-n, --netrc
Makes curl scan the .netrc file in the user's home directory for
login name and password. This is typically used for FTP on Unix.
If used with HTTP, curl enables user authentication. See
netrc(5) and ftp(1) for details on the file format. Curl does
not complain if that file does not have the right permissions
(it should be neither world- nor group-readable). The environ‐
ment variable "HOME" is used to find the home directory.
On Windows two filenames in the home directory are checked:
.netrc and _netrc, preferring the former. Older versions on Win‐
dows checked for _netrc only.
A quick and simple example of how to setup a .netrc to allow
curl to FTP to the machine host.domain.com with user name 'my‐
self' and password 'secret' could look similar to:
machine host.domain.com
login myself
password secret
Providing -n, --netrc multiple times has no extra effect. Dis‐
able it again with --no-netrc.
Example:
curl --netrc https://example.com
See also --netrc-file, -K, --config and -u, --user. This option
is mutually exclusive to --netrc-file and --netrc-optional.
-:, --next
Tells curl to use a separate operation for the following URL and
associated options. This allows you to send several URL re‐
quests, each with their own specific options, for example, such
as different user names or custom requests for each.
-:, --next resets all local options and only global ones have
their values survive over to the operation following the -:,
--next instruction. Global options include -v, --verbose,
--trace, --trace-ascii and --fail-early.
For example, you can do both a GET and a POST in a single com‐
mand line:
curl www1.example.com --next -d postthis www2.example.com
-:, --next can be used several times in a command line
Examples:
curl https://example.com --next -d postthis www2.example.com
curl -I https://example.com --next https://example.net/
See also -Z, --parallel and -K, --config.
--no-alpn
(HTTPS) Disable the ALPN TLS extension. ALPN is enabled by de‐
fault if libcurl was built with an SSL library that supports
ALPN. ALPN is used by a libcurl that supports HTTP/2 to negoti‐
ate HTTP/2 support with the server during https sessions.
Note that this is the negated option name documented. You can
use --alpn to enable ALPN.
Providing --no-alpn multiple times has no extra effect. Disable
it again with --alpn.
Example:
curl --no-alpn https://example.com
See also --no-npn and --http2. --no-alpn requires that the un‐
derlying libcurl was built to support TLS.
-N, --no-buffer
Disables the buffering of the output stream. In normal work sit‐
uations, curl uses a standard buffered output stream that has
the effect that it outputs the data in chunks, not necessarily
exactly when the data arrives. Using this option disables that
buffering.
Note that this is the negated option name documented. You can
use --buffer to enable buffering again.
Providing -N, --no-buffer multiple times has no extra effect.
Disable it again with --buffer.
Example:
curl --no-buffer https://example.com
See also -#, --progress-bar.
--no-clobber
When used in conjunction with the -o, --output, -J, --re‐
mote-header-name, -O, --remote-name, or --remote-name-all op‐
tions, curl avoids overwriting files that already exist. In‐
stead, a dot and a number gets appended to the name of the file
that would be created, up to filename.100 after which it does
not create any file.
Note that this is the negated option name documented. You can
thus use --clobber to enforce the clobbering, even if -J, --re‐
mote-header-name is specified.
Providing --no-clobber multiple times has no extra effect. Dis‐
able it again with --clobber.
Example:
curl --no-clobber --output local/dir/file https://example.com
See also -o, --output and -O, --remote-name. Added in 7.83.0.
--no-keepalive
Disables the use of keepalive messages on the TCP connection.
curl otherwise enables them by default.
Note that this is the negated option name documented. You can
thus use --keepalive to enforce keepalive.
Providing --no-keepalive multiple times has no extra effect.
Disable it again with --keepalive.
Example:
curl --no-keepalive https://example.com
See also --keepalive-time.
--no-npn
(HTTPS) curl never uses NPN, this option has no effect (added in
7.86.0).
Disable the NPN TLS extension. NPN is enabled by default if
libcurl was built with an SSL library that supports NPN. NPN is
used by a libcurl that supports HTTP/2 to negotiate HTTP/2 sup‐
port with the server during https sessions.
Providing --no-npn multiple times has no extra effect. Disable
it again with --npn.
Example:
curl --no-npn https://example.com
See also --no-alpn and --http2. --no-npn requires that the un‐
derlying libcurl was built to support TLS.
--no-progress-meter
Option to switch off the progress meter output without muting or
otherwise affecting warning and informational messages like -s,
--silent does.
Note that this is the negated option name documented. You can
thus use --progress-meter to enable the progress meter again.
Providing --no-progress-meter multiple times has no extra ef‐
fect. Disable it again with --progress-meter.
Example:
curl --no-progress-meter -o store https://example.com
See also -v, --verbose and -s, --silent. Added in 7.67.0.
--no-sessionid
(TLS) Disable curl's use of SSL session-ID caching. By default
all transfers are done using the cache. Note that while nothing
should ever get hurt by attempting to reuse SSL session-IDs,
there seem to be broken SSL implementations in the wild that may
require you to disable this in order for you to succeed.
Note that this is the negated option name documented. You can
thus use --sessionid to enforce session-ID caching.
Providing --no-sessionid multiple times has no extra effect.
Disable it again with --sessionid.
Example:
curl --no-sessionid https://example.com
See also -k, --insecure.
--noproxy <no-proxy-list>
Comma-separated list of hosts for which not to use a proxy, if
one is specified. The only wildcard is a single * character,
which matches all hosts, and effectively disables the proxy.
Each name in this list is matched as either a domain which con‐
tains the hostname, or the hostname itself. For example, lo‐
cal.com would match local.com, local.com:80, and www.local.com,
but not www.notlocal.com.
This option overrides the environment variables that disable the
proxy ('no_proxy' and 'NO_PROXY') (added in 7.53.0). If there is
an environment variable disabling a proxy, you can set the no
proxy list to "" to override it.
IP addresses specified to this option can be provided using CIDR
notation (added in 7.86.0): an appended slash and number speci‐
fies the number of "network bits" out of the address to use in
the comparison. For example "192.168.0.0/16" would match all ad‐
dresses starting with "192.168".
If --noproxy is provided several times, the last set value is
used.
Example:
curl --noproxy "www.example" https://example.com
See also -x, --proxy.
--ntlm-wb
(HTTP) Enables NTLM much in the style --ntlm does, but hand over
the authentication to the separate binary ntlmauth application
that is executed when needed.
Providing --ntlm-wb multiple times has no extra effect.
Example:
curl --ntlm-wb -u user:password https://example.com
See also --ntlm and --proxy-ntlm.
--ntlm (HTTP) Enables NTLM authentication. The NTLM authentication
method was designed by Microsoft and is used by IIS web servers.
It is a proprietary protocol, reverse-engineered by clever peo‐
ple and implemented in curl based on their efforts. This kind of
behavior should not be endorsed, you should encourage everyone
who uses NTLM to switch to a public and documented authentica‐
tion method instead, such as Digest.
If you want to enable NTLM for your proxy authentication, then
use --proxy-ntlm.
Providing --ntlm multiple times has no extra effect.
Example:
curl --ntlm -u user:password https://example.com
See also --proxy-ntlm. --ntlm requires that the underlying
libcurl was built to support TLS. This option is mutually exclu‐
sive to --basic and --negotiate and --digest and --anyauth.
--oauth2-bearer <token>
(IMAP LDAP POP3 SMTP HTTP) Specify the Bearer Token for OAUTH
2.0 server authentication. The Bearer Token is used in conjunc‐
tion with the user name which can be specified as part of the
--url or -u, --user options.
The Bearer Token and user name are formatted according to RFC
6750.
If --oauth2-bearer is provided several times, the last set value
is used.
Example:
curl --oauth2-bearer "mF_9.B5f-4.1JqM" https://example.com
See also --basic, --ntlm and --digest.
--output-dir <dir>
This option specifies the directory in which files should be
stored, when -O, --remote-name or -o, --output are used.
The given output directory is used for all URLs and output op‐
tions on the command line, up until the first -:, --next.
If the specified target directory does not exist, the operation
fails unless --create-dirs is also used.
If --output-dir is provided several times, the last set value is
used.
Example:
curl --output-dir "tmp" -O https://example.com
See also -O, --remote-name and -J, --remote-header-name. Added
in 7.73.0.
-o, --output <file>
Write output to <file> instead of stdout. If you are using {} or
[] to fetch multiple documents, you should quote the URL and you
can use '#' followed by a number in the <file> specifier. That
variable is replaced with the current string for the URL being
fetched. Like in:
curl "http://{one,two}.example.com" -o "file_#1.txt"
or use several variables like:
curl "http://{site,host}.host[1-5].example" -o "#1_#2"
You may use this option as many times as the number of URLs you
have. For example, if you specify two URLs on the same command
line, you can use it like this:
curl -o aa example.com -o bb example.net
and the order of the -o options and the URLs does not matter,
just that the first -o is for the first URL and so on, so the
above command line can also be written as
curl example.com example.net -o aa -o bb
See also the --create-dirs option to create the local directo‐
ries dynamically. Specifying the output as '-' (a single dash)
passes the output to stdout.
To suppress response bodies, you can redirect output to
/dev/null:
curl example.com -o /dev/null
Or for Windows:
curl example.com -o nul
-o, --output can be used several times in a command line
Examples:
curl -o file https://example.com
curl "http://{one,two}.example.com" -o "file_#1.txt"
curl "http://{site,host}.host[1-5].example" -o "#1_#2"
curl -o file https://example.com -o file2 https://example.net
See also -O, --remote-name, --remote-name-all and -J, --re‐
mote-header-name.
--parallel-immediate
When doing parallel transfers, this option instructs curl that
it should rather prefer opening up more connections in parallel
at once rather than waiting to see if new transfers can be added
as multiplexed streams on another connection.
This option is global and does not need to be specified for each
use of --next.
Providing --parallel-immediate multiple times has no extra ef‐
fect. Disable it again with --no-parallel-immediate.
Example:
curl --parallel-immediate -Z https://example.com -o file1 https://example.com -o file2
See also -Z, --parallel and --parallel-max. Added in 7.68.0.
--parallel-max <num>
When asked to do parallel transfers, using -Z, --parallel, this
option controls the maximum amount of transfers to do simultane‐
ously.
This option is global and does not need to be specified for each
use of -:, --next.
The default is 50.
If --parallel-max is provided several times, the last set value
is used.
Example:
curl --parallel-max 100 -Z https://example.com ftp://example.com/
See also -Z, --parallel. Added in 7.66.0.
-Z, --parallel
Makes curl perform its transfers in parallel as compared to the
regular serial manner.
This option is global and does not need to be specified for each
use of --next.
Providing -Z, --parallel multiple times has no extra effect.
Disable it again with --no-parallel.
Example:
curl --parallel https://example.com -o file1 https://example.com -o file2
See also -:, --next and -v, --verbose. Added in 7.66.0.
--pass <phrase>
(SSH TLS) Passphrase for the private key.
If --pass is provided several times, the last set value is used.
Example:
curl --pass secret --key file https://example.com
See also --key and -u, --user.
--path-as-is
Tell curl to not handle sequences of /../ or /./ in the given
URL path. Normally curl squashes or merges them according to
standards but with this option set you tell it not to do that.
Providing --path-as-is multiple times has no extra effect. Dis‐
able it again with --no-path-as-is.
Example:
curl --path-as-is https://example.com/../../etc/passwd
See also --request-target.
--pinnedpubkey <hashes>
(TLS) Tells curl to use the specified public key file (or
hashes) to verify the peer. This can be a path to a file which
contains a single public key in PEM or DER format, or any number
of base64 encoded sha256 hashes preceded by 'sha256//' and sepa‐
rated by ';'.
When negotiating a TLS or SSL connection, the server sends a
certificate indicating its identity. A public key is extracted
from this certificate and if it does not exactly match the pub‐
lic key provided to this option, curl aborts the connection be‐
fore sending or receiving any data.
This option is independent of option -k, --insecure. If you use
both options together then the peer is still verified by public
key.
PEM/DER support:
OpenSSL and GnuTLS, wolfSSL (added in 7.43.0), mbedTLS , Secure
Transport macOS 10.7+/iOS 10+ (7.54.1), Schannel (7.58.1)
sha256 support:
OpenSSL, GnuTLS and wolfSSL, mbedTLS (added in 7.47.0), Secure
Transport macOS 10.7+/iOS 10+ (7.54.1), Schannel (7.58.1)
Other SSL backends not supported.
If --pinnedpubkey is provided several times, the last set value
is used.
Examples:
curl --pinnedpubkey keyfile https://example.com
curl --pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com
See also --hostpubsha256.
--post301
(HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST
requests into GET requests when following a 301 redirection. The
non-RFC behavior is ubiquitous in web browsers, so curl does the
conversion by default to maintain consistency. However, a server
may require a POST to remain a POST after such a redirection.
This option is meaningful only when using -L, --location.
Providing --post301 multiple times has no extra effect. Disable
it again with --no-post301.
Example:
curl --post301 --location -d "data" https://example.com
See also --post302, --post303 and -L, --location.
--post302
(HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST
requests into GET requests when following a 302 redirection. The
non-RFC behavior is ubiquitous in web browsers, so curl does the
conversion by default to maintain consistency. However, a server
may require a POST to remain a POST after such a redirection.
This option is meaningful only when using -L, --location.
Providing --post302 multiple times has no extra effect. Disable
it again with --no-post302.
Example:
curl --post302 --location -d "data" https://example.com
See also --post301, --post303 and -L, --location.
--post303
(HTTP) Tells curl to violate RFC 7231/6.4.4 and not convert POST
requests into GET requests when following 303 redirections. A
server may require a POST to remain a POST after a 303 redirec‐
tion. This option is meaningful only when using -L, --location.
Providing --post303 multiple times has no extra effect. Disable
it again with --no-post303.
Example:
curl --post303 --location -d "data" https://example.com
See also --post302, --post301 and -L, --location.
--preproxy [protocol://]host[:port]
Use the specified SOCKS proxy before connecting to an HTTP or
HTTPS -x, --proxy. In such a case curl first connects to the
SOCKS proxy and then connects (through SOCKS) to the HTTP or
HTTPS proxy. Hence pre proxy.
The pre proxy string should be specified with a protocol:// pre‐
fix to specify alternative proxy protocols. Use socks4://,
socks4a://, socks5:// or socks5h:// to request the specific
SOCKS version to be used. No protocol specified makes curl de‐
fault to SOCKS4.
If the port number is not specified in the proxy string, it is
assumed to be 1080.
User and password that might be provided in the proxy string are
URL decoded by curl. This allows you to pass in special charac‐
ters such as @ by using %40 or pass in a colon with %3a.
If --preproxy is provided several times, the last set value is
used.
Example:
curl --preproxy socks5://proxy.example -x http://http.example https://example.com
See also -x, --proxy and --socks5. Added in 7.52.0.
-#, --progress-bar
Make curl display transfer progress as a simple progress bar in‐
stead of the standard, more informational, meter.
This progress bar draws a single line of '#' characters across
the screen and shows a percentage if the transfer size is known.
For transfers without a known size, there is a space ship
(-=o=-) that moves back and forth but only while data is being
transferred, with a set of flying hash sign symbols on top.
This option is global and does not need to be specified for each
use of --next.
Providing -#, --progress-bar multiple times has no extra effect.
Disable it again with --no-progress-bar.
Example:
curl -# -O https://example.com
See also --styled-output.
--proto-default <protocol>
Tells curl to use protocol for any URL missing a scheme name.
An unknown or unsupported protocol causes error CURLE_UNSUP‐
PORTED_PROTOCOL (1).
This option does not change the default proxy protocol (http).
Without this option set, curl guesses protocol based on the host
name, see --url for details.
If --proto-default is provided several times, the last set value
is used.
Example:
curl --proto-default https ftp.example.com
See also --proto and --proto-redir.
--proto-redir <protocols>
Tells curl to limit what protocols it may use on redirect. Pro‐
tocols denied by --proto are not overridden by this option. See
--proto for how protocols are represented.
Example, allow only HTTP and HTTPS on redirect:
curl --proto-redir -all,http,https http://example.com
By default curl only allows HTTP, HTTPS, FTP and FTPS on redi‐
rects (added in 7.65.2). Specifying all or +all enables all pro‐
tocols on redirects, which is not good for security.
If --proto-redir is provided several times, the last set value
is used.
Example:
curl --proto-redir =http,https https://example.com
See also --proto.
--proto <protocols>
Tells curl to limit what protocols it may use for transfers.
Protocols are evaluated left to right, are comma separated, and
are each a protocol name or 'all', optionally prefixed by zero
or more modifiers. Available modifiers are:
+ Permit this protocol in addition to protocols already permit‐
ted (this is the default if no modifier is used).
- Deny this protocol, removing it from the list of protocols
already permitted.
= Permit only this protocol (ignoring the list already permit‐
ted), though subject to later modification by subsequent en‐
tries in the comma separated list.
For example:
--proto -ftps uses the default protocols, but disables ftps
--proto -all,https,+http
only enables http and https
--proto =http,https
also only enables http and https
Unknown and disabled protocols produce a warning. This allows
scripts to safely rely on being able to disable potentially dan‐
gerous protocols, without relying upon support for that protocol
being built into curl to avoid an error.
This option can be used multiple times, in which case the effect
is the same as concatenating the protocols into one instance of
the option.
If --proto is provided several times, the last set value is
used.
Example:
curl --proto =http,https,sftp https://example.com
See also --proto-redir and --proto-default.
--proxy-anyauth
Tells curl to pick a suitable authentication method when commu‐
nicating with the given HTTP proxy. This might cause an extra
request/response round-trip.
Providing --proxy-anyauth multiple times has no extra effect.
Example:
curl --proxy-anyauth --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-basic and --proxy-digest.
--proxy-basic
Tells curl to use HTTP Basic authentication when communicating
with the given proxy. Use --basic for enabling HTTP Basic with a
remote host. Basic is the default authentication method curl
uses with proxies.
Providing --proxy-basic multiple times has no extra effect.
Example:
curl --proxy-basic --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-anyauth and --proxy-digest.
--proxy-ca-native
(TLS) Tells curl to use the CA store from the native operating
system to verify the HTTPS proxy. By default, curl uses a CA
store provided in a single file or directory, but when using
this option it interfaces the operating system's own vault.
This option only works for curl on Windows when built to use
OpenSSL. When curl on Windows is built to use Schannel, this
feature is implied and curl then only uses the native CA store.
curl built with wolfSSL also supports this option (added in
8.3.0).
Providing --proxy-ca-native multiple times has no extra effect.
Disable it again with --no-proxy-ca-native.
Example:
curl --ca-native https://example.com
See also --cacert, --capath and -k, --insecure. Added in 8.2.0.
--proxy-cacert <file>
Same as --cacert but used in HTTPS proxy context.
If --proxy-cacert is provided several times, the last set value
is used.
Example:
curl --proxy-cacert CA-file.txt -x https://proxy https://example.com
See also --proxy-capath, --cacert, --capath and -x, --proxy.
Added in 7.52.0.
--proxy-capath <dir>
Same as --capath but used in HTTPS proxy context.
If --proxy-capath is provided several times, the last set value
is used.
Example:
curl --proxy-capath /local/directory -x https://proxy https://example.com
See also --proxy-cacert, -x, --proxy and --capath. Added in
7.52.0.
--proxy-cert-type <type>
Same as --cert-type but used in HTTPS proxy context.
If --proxy-cert-type is provided several times, the last set
value is used.
Example:
curl --proxy-cert-type PEM --proxy-cert file -x https://proxy https://example.com
See also --proxy-cert. Added in 7.52.0.
--proxy-cert <cert[:passwd]>
Same as -E, --cert but used in HTTPS proxy context.
If --proxy-cert is provided several times, the last set value is
used.
Example:
curl --proxy-cert file -x https://proxy https://example.com
See also --proxy-cert-type. Added in 7.52.0.
--proxy-ciphers <list>
Same as --ciphers but used in HTTPS proxy context.
Specifies which ciphers to use in the connection to the HTTPS
proxy. The list of ciphers must specify valid ciphers. Read up
on SSL cipher list details on this URL:
https://curl.se/docs/ssl-ciphers.html
If --proxy-ciphers is provided several times, the last set value
is used.
Example:
curl --proxy-ciphers ECDHE-ECDSA-AES256-CCM8 -x https://proxy https://example.com
See also --ciphers, --curves and -x, --proxy. Added in 7.52.0.
--proxy-crlfile <file>
Same as --crlfile but used in HTTPS proxy context.
If --proxy-crlfile is provided several times, the last set value
is used.
Example:
curl --proxy-crlfile rejects.txt -x https://proxy https://example.com
See also --crlfile and -x, --proxy. Added in 7.52.0.
--proxy-digest
Tells curl to use HTTP Digest authentication when communicating
with the given proxy. Use --digest for enabling HTTP Digest with
a remote host.
Providing --proxy-digest multiple times has no extra effect.
Example:
curl --proxy-digest --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-anyauth and --proxy-basic.
--proxy-header <header/@file>
(HTTP) Extra header to include in the request when sending HTTP
to a proxy. You may specify any number of extra headers. This is
the equivalent option to -H, --header but is for proxy communi‐
cation only like in CONNECT requests when you want a separate
header sent to the proxy to what is sent to the actual remote
host.
curl makes sure that each header you add/replace is sent with
the proper end-of-line marker, you should thus not add that as a
part of the header content: do not add newlines or carriage re‐
turns, they only mess things up for you.
Headers specified with this option are not included in requests
that curl knows are not be sent to a proxy.
This option can take an argument in @filename style, which then
adds a header for each line in the input file (added in 7.55.0).
Using @- makes curl read the headers from stdin.
This option can be used multiple times to add/replace/remove
multiple headers.
--proxy-header can be used several times in a command line
Examples:
curl --proxy-header "X-First-Name: Joe" -x http://proxy https://example.com
curl --proxy-header "User-Agent: surprise" -x http://proxy https://example.com
curl --proxy-header "Host:" -x http://proxy https://example.com
See also -x, --proxy.
--proxy-http2
(HTTP) Tells curl to try negotiate HTTP version 2 with an HTTPS
proxy. The proxy might still only offer HTTP/1 and then curl
sticks to using that version.
This has no effect for any other kinds of proxies.
Providing --proxy-http2 multiple times has no extra effect.
Disable it again with --no-proxy-http2.
Example:
curl --proxy-http2 -x proxy https://example.com
See also -x, --proxy. --proxy-http2 requires that the underlying
libcurl was built to support HTTP/2. Added in 8.1.0.
--proxy-insecure
Same as -k, --insecure but used in HTTPS proxy context.
Providing --proxy-insecure multiple times has no extra effect.
Disable it again with --no-proxy-insecure.
Example:
curl --proxy-insecure -x https://proxy https://example.com
See also -x, --proxy and -k, --insecure. Added in 7.52.0.
--proxy-key-type <type>
Same as --key-type but used in HTTPS proxy context.
If --proxy-key-type is provided several times, the last set
value is used.
Example:
curl --proxy-key-type DER --proxy-key here -x https://proxy https://example.com
See also --proxy-key and -x, --proxy. Added in 7.52.0.
--proxy-key <key>
Same as --key but used in HTTPS proxy context.
If --proxy-key is provided several times, the last set value is
used.
Example:
curl --proxy-key here -x https://proxy https://example.com
See also --proxy-key-type and -x, --proxy. Added in 7.52.0.
--proxy-negotiate
Tells curl to use HTTP Negotiate (SPNEGO) authentication when
communicating with the given proxy. Use --negotiate for enabling
HTTP Negotiate (SPNEGO) with a remote host.
Providing --proxy-negotiate multiple times has no extra effect.
Example:
curl --proxy-negotiate --proxy-user user:passwd -x proxy https://example.com
See also --proxy-anyauth and --proxy-basic.
--proxy-ntlm
Tells curl to use HTTP NTLM authentication when communicating
with the given proxy. Use --ntlm for enabling NTLM with a remote
host.
Providing --proxy-ntlm multiple times has no extra effect.
Example:
curl --proxy-ntlm --proxy-user user:passwd -x http://proxy https://example.com
See also --proxy-negotiate and --proxy-anyauth.
--proxy-pass <phrase>
Same as --pass but used in HTTPS proxy context.
If --proxy-pass is provided several times, the last set value is
used.
Example:
curl --proxy-pass secret --proxy-key here -x https://proxy https://example.com
See also -x, --proxy and --proxy-key. Added in 7.52.0.
--proxy-pinnedpubkey <hashes>
(TLS) Tells curl to use the specified public key file (or
hashes) to verify the proxy. This can be a path to a file which
contains a single public key in PEM or DER format, or any number
of base64 encoded sha256 hashes preceded by 'sha256//' and sepa‐
rated by ';'.
When negotiating a TLS or SSL connection, the server sends a
certificate indicating its identity. A public key is extracted
from this certificate and if it does not exactly match the pub‐
lic key provided to this option, curl aborts the connection be‐
fore sending or receiving any data.
If --proxy-pinnedpubkey is provided several times, the last set
value is used.
Examples:
curl --proxy-pinnedpubkey keyfile https://example.com
curl --proxy-pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com
See also --pinnedpubkey and -x, --proxy. Added in 7.59.0.
--proxy-service-name <name>
This option allows you to change the service name for proxy ne‐
gotiation.
If --proxy-service-name is provided several times, the last set
value is used.
Example:
curl --proxy-service-name "shrubbery" -x proxy https://example.com
See also --service-name and -x, --proxy.
--proxy-ssl-allow-beast
Same as --ssl-allow-beast but used in HTTPS proxy context.
Providing --proxy-ssl-allow-beast multiple times has no extra
effect. Disable it again with --no-proxy-ssl-allow-beast.
Example:
curl --proxy-ssl-allow-beast -x https://proxy https://example.com
See also --ssl-allow-beast and -x, --proxy. Added in 7.52.0.
--proxy-ssl-auto-client-cert
Same as --ssl-auto-client-cert but used in HTTPS proxy context.
Providing --proxy-ssl-auto-client-cert multiple times has no ex‐
tra effect. Disable it again with
--no-proxy-ssl-auto-client-cert.
Example:
curl --proxy-ssl-auto-client-cert -x https://proxy https://example.com
See also --ssl-auto-client-cert and -x, --proxy. Added in
7.77.0.
--proxy-tls13-ciphers <ciphersuite list>
(TLS) Specifies which cipher suites to use in the connection to
your HTTPS proxy when it negotiates TLS 1.3. The list of ciphers
suites must specify valid ciphers. Read up on TLS 1.3 cipher
suite details on this URL:
https://curl.se/docs/ssl-ciphers.html
This option is currently used only when curl is built to use
OpenSSL 1.1.1 or later. If you are using a different SSL backend
you can try setting TLS 1.3 cipher suites by using the
--proxy-ciphers option.
If --proxy-tls13-ciphers is provided several times, the last set
value is used.
Example:
curl --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy https://example.com
See also --tls13-ciphers, --curves and --proxy-ciphers. Added in
7.61.0.
--proxy-tlsauthtype <type>
Same as --tlsauthtype but used in HTTPS proxy context.
If --proxy-tlsauthtype is provided several times, the last set
value is used.
Example:
curl --proxy-tlsauthtype SRP -x https://proxy https://example.com
See also -x, --proxy and --proxy-tlsuser. Added in 7.52.0.
--proxy-tlspassword <string>
Same as --tlspassword but used in HTTPS proxy context.
If --proxy-tlspassword is provided several times, the last set
value is used.
Example:
curl --proxy-tlspassword passwd -x https://proxy https://example.com
See also -x, --proxy and --proxy-tlsuser. Added in 7.52.0.
--proxy-tlsuser <name>
Same as --tlsuser but used in HTTPS proxy context.
If --proxy-tlsuser is provided several times, the last set value
is used.
Example:
curl --proxy-tlsuser smith -x https://proxy https://example.com
See also -x, --proxy and --proxy-tlspassword. Added in 7.52.0.
--proxy-tlsv1
Same as -1, --tlsv1 but used in HTTPS proxy context.
Providing --proxy-tlsv1 multiple times has no extra effect.
Example:
curl --proxy-tlsv1 -x https://proxy https://example.com
See also -x, --proxy. Added in 7.52.0.
-U, --proxy-user <user:password>
Specify the user name and password to use for proxy authentica‐
tion.
If you use a Windows SSPI-enabled curl binary and do either Ne‐
gotiate or NTLM authentication then you can tell curl to select
the user name and password from your environment by specifying a
single colon with this option: "-U :".
On systems where it works, curl hides the given option argument
from process listings. This is not enough to protect credentials
from possibly getting seen by other users on the same system as
they still are visible for a moment before cleared. Such sensi‐
tive data should be retrieved from a file instead or similar and
never used in clear text in a command line.
If -U, --proxy-user is provided several times, the last set
value is used.
Example:
curl --proxy-user name:pwd -x proxy https://example.com
See also --proxy-pass.
-x, --proxy [protocol://]host[:port]
Use the specified proxy.
The proxy string can be specified with a protocol:// prefix. No
protocol specified or http:// it is treated as an HTTP proxy.
Use socks4://, socks4a://, socks5:// or socks5h:// to request a
specific SOCKS version to be used.
Unix domain sockets are supported for socks proxy. Set localhost
for the host part. e.g. socks5h://localhost/path/to/socket.sock
HTTPS proxy support works set with the https:// protocol prefix
for OpenSSL and GnuTLS (added in 7.52.0). It also works for
BearSSL, mbedTLS, rustls, Schannel, Secure Transport and wolfSSL
(added in 7.87.0).
Unrecognized and unsupported proxy protocols cause an error
(added in 7.52.0). Ancient curl versions ignored unknown
schemes and used http:// instead.
If the port number is not specified in the proxy string, it is
assumed to be 1080.
This option overrides existing environment variables that set
the proxy to use. If there is an environment variable setting a
proxy, you can set proxy to "" to override it.
All operations that are performed over an HTTP proxy are trans‐
parently converted to HTTP. It means that certain protocol spe‐
cific operations might not be available. This is not the case if
you can tunnel through the proxy, as one with the -p, --proxy‐
tunnel option.
User and password that might be provided in the proxy string are
URL decoded by curl. This allows you to pass in special charac‐
ters such as @ by using %40 or pass in a colon with %3a.
The proxy host can be specified the same way as the proxy envi‐
ronment variables, including the protocol prefix (http://) and
the embedded user + password.
When a proxy is used, the active FTP mode as set with -P,
--ftp-port, cannot be used.
If -x, --proxy is provided several times, the last set value is
used.
Example:
curl --proxy http://proxy.example https://example.com
See also --socks5 and --proxy-basic.
--proxy1.0 <host[:port]>
Use the specified HTTP 1.0 proxy. If the port number is not
specified, it is assumed at port 1080.
The only difference between this and the HTTP proxy option -x,
--proxy, is that attempts to use CONNECT through the proxy spec‐
ifies an HTTP 1.0 protocol instead of the default HTTP 1.1.
Providing --proxy1.0 multiple times has no extra effect.
Example:
curl --proxy1.0 -x http://proxy https://example.com
See also -x, --proxy, --socks5 and --preproxy.
-p, --proxytunnel
When an HTTP proxy is used -x, --proxy, this option makes curl
tunnel the traffic through the proxy. The tunnel approach is
made with the HTTP proxy CONNECT request and requires that the
proxy allows direct connect to the remote port number curl wants
to tunnel through to.
To suppress proxy CONNECT response headers when curl is set to
output headers use --suppress-connect-headers.
Providing -p, --proxytunnel multiple times has no extra effect.
Disable it again with --no-proxytunnel.
Example:
curl --proxytunnel -x http://proxy https://example.com
See also -x, --proxy.
--pubkey <key>
(SFTP SCP) Public key file name. Allows you to provide your pub‐
lic key in this separate file.
curl attempts to automatically extract the public key from the
private key file, so passing this option is generally not re‐
quired. Note that this public key extraction requires libcurl to
be linked against a copy of libssh2 1.2.8 or higher that is it‐
self linked against OpenSSL.
If --pubkey is provided several times, the last set value is
used.
Example:
curl --pubkey file.pub sftp://example.com/
See also --pass.
-Q, --quote <command>
(FTP SFTP) Send an arbitrary command to the remote FTP or SFTP
server. Quote commands are sent BEFORE the transfer takes place
(just after the initial PWD command in an FTP transfer, to be
exact). To make commands take place after a successful transfer,
prefix them with a dash '-'.
(FTP only) To make commands be sent after curl has changed the
working directory, just before the file transfer command(s),
prefix the command with a '+'. This is not performed when a di‐
rectory listing is performed.
You may specify any number of commands.
By default curl stops at first failure. To make curl continue
even if the command fails, prefix the command with an asterisk
(*). Otherwise, if the server returns failure for one of the
commands, the entire operation is aborted.
You must send syntactically correct FTP commands as RFC 959 de‐
fines to FTP servers, or one of the commands listed below to
SFTP servers.
SFTP is a binary protocol. Unlike for FTP, curl interprets SFTP
quote commands itself before sending them to the server. File
names may be quoted shell-style to embed spaces or special char‐
acters. Following is the list of all supported SFTP quote com‐
mands:
"atime date file"
The atime command sets the last access time of the file
named by the file operand. The <date expression> can be
all sorts of date strings, see the curl_getdate(3) man
page for date expression details. (Added in 7.73.0)
"chgrp group file"
The chgrp command sets the group ID of the file named by
the file operand to the group ID specified by the group
operand. The group operand is a decimal integer group ID.
"chmod mode file"
The chmod command modifies the file mode bits of the
specified file. The mode operand is an octal integer mode
number.
"chown user file"
The chown command sets the owner of the file named by the
file operand to the user ID specified by the user
operand. The user operand is a decimal integer user ID.
"ln source_file target_file"
The ln and symlink commands create a symbolic link at the
target_file location pointing to the source_file loca‐
tion.
"mkdir directory_name"
The mkdir command creates the directory named by the di‐
rectory_name operand.
"mtime date file"
The mtime command sets the last modification time of the
file named by the file operand. The <date expression> can
be all sorts of date strings, see the curl_getdate(3) man
page for date expression details. (Added in 7.73.0)
"pwd" The pwd command returns the absolute path name of the
current working directory.
"rename source target"
The rename command renames the file or directory named by
the source operand to the destination path named by the
target operand.
"rm file"
The rm command removes the file specified by the file
operand.
"rmdir directory"
The rmdir command removes the directory entry specified
by the directory operand, provided it is empty.
"symlink source_file target_file"
See ln.
-Q, --quote can be used several times in a command line
Example:
curl --quote "DELE file" ftp://example.com/foo
See also -X, --request.
--random-file <file>
Deprecated option. This option is ignored (added in 7.84.0).
Prior to that it only had an effect on curl if built to use old
versions of OpenSSL.
Specify the path name to file containing random data. The data
may be used to seed the random engine for SSL connections.
If --random-file is provided several times, the last set value
is used.
Example:
curl --random-file rubbish https://example.com
See also --egd-file.
-r, --range <range>
(HTTP FTP SFTP FILE) Retrieve a byte range (i.e. a partial docu‐
ment) from an HTTP/1.1, FTP or SFTP server or a local FILE.
Ranges can be specified in a number of ways.
0-499 specifies the first 500 bytes
500-999 specifies the second 500 bytes
-500 specifies the last 500 bytes
9500- specifies the bytes from offset 9500 and forward
0-0,-1 specifies the first and last byte only(*)(HTTP)
100-199,500-599
specifies two separate 100-byte ranges(*) (HTTP)
(*) = NOTE that this causes the server to reply with a multipart
response, which is returned as-is by curl! Parsing or otherwise
transforming this response is the responsibility of the caller.
Only digit characters (0-9) are valid in the 'start' and 'stop'
fields of the 'start-stop' range syntax. If a non-digit charac‐
ter is given in the range, the server's response is unspecified,
depending on the server's configuration.
Many HTTP/1.1 servers do not have this feature enabled, so that
when you attempt to get a range, curl instead gets the whole
document.
FTP and SFTP range downloads only support the simple
'start-stop' syntax (optionally with one of the numbers omit‐
ted). FTP use depends on the extended FTP command SIZE.
If -r, --range is provided several times, the last set value is
used.
Example:
curl --range 22-44 https://example.com
See also -C, --continue-at and -a, --append.
--rate <max request rate>
Specify the maximum transfer frequency you allow curl to use -
in number of transfer starts per time unit (sometimes called re‐
quest rate). Without this option, curl starts the next transfer
as fast as possible.
If given several URLs and a transfer completes faster than the
allowed rate, curl waits until the next transfer is started to
maintain the requested rate. This option has no effect when -Z,
--parallel is used.
The request rate is provided as "N/U" where N is an integer num‐
ber and U is a time unit. Supported units are 's' (second), 'm'
(minute), 'h' (hour) and 'd' /(day, as in a 24 hour unit). The
default time unit, if no "/U" is provided, is number of trans‐
fers per hour.
If curl is told to allow 10 requests per minute, it does not
start the next request until 6 seconds have elapsed since the
previous transfer was started.
This function uses millisecond resolution. If the allowed fre‐
quency is set more than 1000 per second, it instead runs unre‐
stricted.
When retrying transfers, enabled with --retry, the separate
retry delay logic is used and not this setting.
This option is global and does not need to be specified for each
use of --next.
If --rate is provided several times, the last set value is used.
Examples:
curl --rate 2/s https://example.com ...
curl --rate 3/h https://example.com ...
curl --rate 14/m https://example.com ...
See also --limit-rate and --retry-delay. Added in 7.84.0.
--raw (HTTP) When used, it disables all internal HTTP decoding of con‐
tent or transfer encodings and instead makes them passed on un‐
altered, raw.
Providing --raw multiple times has no extra effect. Disable it
again with --no-raw.
Example:
curl --raw https://example.com
See also --tr-encoding.
-e, --referer <URL>
(HTTP) Sends the "Referrer Page" information to the HTTP server.
This can also be set with the -H, --header flag of course. When
used with -L, --location you can append ";auto" to the -e,
--referer URL to make curl automatically set the previous URL
when it follows a Location: header. The ";auto" string can be
used alone, even if you do not set an initial -e, --referer.
If -e, --referer is provided several times, the last set value
is used.
Examples:
curl --referer "https://fake.example" https://example.com
curl --referer "https://fake.example;auto" -L https://example.com
curl --referer ";auto" -L https://example.com
See also -A, --user-agent and -H, --header.
-J, --remote-header-name
(HTTP) This option tells the -O, --remote-name option to use the
server-specified Content-Disposition filename instead of ex‐
tracting a filename from the URL. If the server-provided file
name contains a path, that is stripped off before the file name
is used.
The file is saved in the current directory, or in the directory
specified with --output-dir.
If the server specifies a file name and a file with that name
already exists in the destination directory, it is not overwrit‐
ten and an error occurs - unless you allow it by using the
--clobber option. If the server does not specify a file name
then this option has no effect.
There is no attempt to decode %-sequences (yet) in the provided
file name, so this option may provide you with rather unexpected
file names.
This feature uses the name from the "filename" field, it does
not yet support the "filename*" field (filenames with explicit
character sets).
WARNING: Exercise judicious use of this option, especially on
Windows. A rogue server could send you the name of a DLL or
other file that could be loaded automatically by Windows or some
third party software.
Providing -J, --remote-header-name multiple times has no extra
effect. Disable it again with --no-remote-header-name.
Example:
curl -OJ https://example.com/file
See also -O, --remote-name.
--remote-name-all
This option changes the default action for all given URLs to be
dealt with as if -O, --remote-name were used for each one. So if
you want to disable that for a specific URL after --re‐
mote-name-all has been used, you must use "-o -" or --no-re‐
mote-name.
Providing --remote-name-all multiple times has no extra effect.
Disable it again with --no-remote-name-all.
Example:
curl --remote-name-all ftp://example.com/file1 ftp://example.com/file2
See also -O, --remote-name.
-O, --remote-name
Write output to a local file named like the remote file we get.
(Only the file part of the remote file is used, the path is cut
off.)
The file is saved in the current working directory. If you want
the file saved in a different directory, make sure you change
the current working directory before invoking curl with this op‐
tion or use --output-dir.
The remote file name to use for saving is extracted from the
given URL, nothing else, and if it already exists it is over‐
written. If you want the server to be able to choose the file
name refer to -J, --remote-header-name which can be used in ad‐
dition to this option. If the server chooses a file name and
that name already exists it is not overwritten.
There is no URL decoding done on the file name. If it has %20 or
other URL encoded parts of the name, they end up as-is as file
name.
You may use this option as many times as the number of URLs you
have.
-O, --remote-name can be used several times in a command line
Example:
curl -O https://example.com/filename
See also --remote-name-all, --output-dir and -J, --re‐
mote-header-name.
-R, --remote-time
Makes curl attempt to figure out the timestamp of the remote
file that is getting downloaded, and if that is available make
the local file get that same timestamp.
Providing -R, --remote-time multiple times has no extra effect.
Disable it again with --no-remote-time.
Example:
curl --remote-time -o foo https://example.com
See also -O, --remote-name and -z, --time-cond.
--remove-on-error
When curl returns an error when told to save output in a local
file, this option removes that saved file before exiting. This
prevents curl from leaving a partial file in the case of an er‐
ror during transfer.
If the output is not a file, this option has no effect.
Providing --remove-on-error multiple times has no extra effect.
Disable it again with --no-remove-on-error.
Example:
curl --remove-on-error -o output https://example.com
See also -f, --fail. Added in 7.83.0.
--request-target <path>
(HTTP) Tells curl to use an alternative "target" (path) instead
of using the path as provided in the URL. Particularly useful
when wanting to issue HTTP requests without leading slash or
other data that does not follow the regular URL pattern, like
"OPTIONS *".
curl passes on the verbatim string you give it its the request
without any filter or other safe guards. That includes white
space and control characters.
If --request-target is provided several times, the last set
value is used.
Example:
curl --request-target "*" -X OPTIONS https://example.com
See also -X, --request. Added in 7.55.0.
-X, --request <method>
Change the method to use when starting the transfer.
curl passes on the verbatim string you give it its the request
without any filter or other safe guards. That includes white
space and control characters.
HTTP Specifies a custom request method to use when
communicating with the HTTP server. The specified
request method is used instead of the method oth‐
erwise used (which defaults to GET). Read the
HTTP 1.1 specification for details and explana‐
tions. Common additional HTTP requests include
PUT and DELETE, but related technologies like
WebDAV offers PROPFIND, COPY, MOVE and more.
Normally you do not need this option. All sorts
of GET, HEAD, POST and PUT requests are rather
invoked by using dedicated command line options.
This option only changes the actual word used in
the HTTP request, it does not alter the way curl
behaves. So for example if you want to make a
proper HEAD request, using -X HEAD does not suf‐
fice. You need to use the -I, --head option.
The method string you set with -X, --request is
used for all requests, which if you for example
use -L, --location may cause unintended side-ef‐
fects when curl does not change request method
according to the HTTP 30x response codes - and
similar.
FTP Specifies a custom FTP command to use instead of
LIST when doing file lists with FTP.
POP3 Specifies a custom POP3 command to use instead of
LIST or RETR.
IMAP Specifies a custom IMAP command to use instead of
LIST.
SMTP Specifies a custom SMTP command to use instead of
HELP or VRFY.
If -X, --request is provided several times, the last set value
is used.
Examples:
curl -X "DELETE" https://example.com
curl -X NLST ftp://example.com/
See also --request-target.
--resolve <[+]host:port:addr[,addr]...>
Provide a custom address for a specific host and port pair. Us‐
ing this, you can make the curl requests(s) use a specified ad‐
dress and prevent the otherwise normally resolved address to be
used. Consider it a sort of /etc/hosts alternative provided on
the command line. The port number should be the number used for
the specific protocol the host is used for. It means you need
several entries if you want to provide address for the same host
but different ports.
By specifying '*' as host you can tell curl to resolve any host
and specific port pair to the specified address. Wildcard is re‐
solved last so any --resolve with a specific host and port is
used first.
The provided address set by this option is used even if -4,
--ipv4 or -6, --ipv6 is set to make curl use another IP version.
By prefixing the host with a '+' you can make the entry time out
after curl's default timeout (1 minute). Note that this only
makes sense for long running parallel transfers with a lot of
files. In such cases, if this option is used curl tries to re‐
solve the host as it normally would once the timeout has ex‐
pired.
Support for providing the IP address within [brackets] was added
in 7.57.0.
Support for providing multiple IP addresses per entry was added
in 7.59.0.
Support for resolving with wildcard was added in 7.64.0.
Support for the '+' prefix was was added in 7.75.0.
--resolve can be used several times in a command line
Example:
curl --resolve example.com:443:127.0.0.1 https://example.com
See also --connect-to and --alt-svc.
--retry-all-errors
Retry on any error. This option is used together with --retry.
This option is the "sledgehammer" of retrying. Do not use this
option by default (for example in your curlrc), there may be un‐
intended consequences such as sending or receiving duplicate
data. Do not use with redirected input or output. You'd be much
better off handling your unique problems in shell script. Please
read the example below.
WARNING: For server compatibility curl attempts to retry failed
flaky transfers as close as possible to how they were started,
but this is not possible with redirected input or output. For
example, before retrying it removes output data from a failed
partial transfer that was written to an output file. However
this is not true of data redirected to a | pipe or > file, which
are not reset. We strongly suggest you do not parse or record
output via redirect in combination with this option, since you
may receive duplicate data.
By default curl does not return error for transfers with an HTTP
response code that indicates an HTTP error, if the transfer was
successful. For example, if a server replies 404 Not Found and
the reply is fully received then that is not an error. When
--retry is used then curl retries on some HTTP response codes
that indicate transient HTTP errors, but that does not include
most 4xx response codes such as 404. If you want to retry on all
response codes that indicate HTTP errors (4xx and 5xx) then com‐
bine with -f, --fail.
Providing --retry-all-errors multiple times has no extra effect.
Disable it again with --no-retry-all-errors.
Example:
curl --retry 5 --retry-all-errors https://example.com
See also --retry. Added in 7.71.0.
--retry-connrefused
In addition to the other conditions, consider ECONNREFUSED as a
transient error too for --retry. This option is used together
with --retry.
Providing --retry-connrefused multiple times has no extra ef‐
fect. Disable it again with --no-retry-connrefused.
Example:
curl --retry-connrefused --retry 7 https://example.com
See also --retry and --retry-all-errors. Added in 7.52.0.
--retry-delay <seconds>
Make curl sleep this amount of time before each retry when a
transfer has failed with a transient error (it changes the de‐
fault backoff time algorithm between retries). This option is
only interesting if --retry is also used. Setting this delay to
zero makes curl use the default backoff time.
If --retry-delay is provided several times, the last set value
is used.
Example:
curl --retry-delay 5 --retry 7 https://example.com
See also --retry.
--retry-max-time <seconds>
The retry timer is reset before the first transfer attempt. Re‐
tries are done as usual (see --retry) as long as the timer has
not reached this given limit. Notice that if the timer has not
reached the limit, the request is made and while performing, it
may take longer than this given time period. To limit a single
request's maximum time, use -m, --max-time. Set this option to
zero to not timeout retries.
If --retry-max-time is provided several times, the last set
value is used.
Example:
curl --retry-max-time 30 --retry 10 https://example.com
See also --retry.
--retry <num>
If a transient error is returned when curl tries to perform a
transfer, it retries this number of times before giving up. Set‐
ting the number to 0 makes curl do no retries (which is the de‐
fault). Transient error means either: a timeout, an FTP 4xx re‐
sponse code or an HTTP 408, 429, 500, 502, 503 or 504 response
code.
When curl is about to retry a transfer, it first waits one sec‐
ond and then for all forthcoming retries it doubles the waiting
time until it reaches 10 minutes which then remains delay be‐
tween the rest of the retries. By using --retry-delay you dis‐
able this exponential backoff algorithm. See also
--retry-max-time to limit the total time allowed for retries.
curl complies with the Retry-After: response header if one was
present to know when to issue the next retry (added in 7.66.0).
If --retry is provided several times, the last set value is
used.
Example:
curl --retry 7 https://example.com
See also --retry-max-time.
--sasl-authzid <identity>
Use this authorization identity (authzid), during SASL PLAIN au‐
thentication, in addition to the authentication identity (auth‐
cid) as specified by -u, --user.
If the option is not specified, the server derives the authzid
from the authcid, but if specified, and depending on the server
implementation, it may be used to access another user's inbox,
that the user has been granted access to, or a shared mailbox
for example.
If --sasl-authzid is provided several times, the last set value
is used.
Example:
curl --sasl-authzid zid imap://example.com/
See also --login-options. Added in 7.66.0.
--sasl-ir
Enable initial response in SASL authentication.
Providing --sasl-ir multiple times has no extra effect. Disable
it again with --no-sasl-ir.
Example:
curl --sasl-ir imap://example.com/
See also --sasl-authzid.
--service-name <name>
This option allows you to change the service name for SPNEGO.
If --service-name is provided several times, the last set value
is used.
Example:
curl --service-name sockd/server https://example.com
See also --negotiate and --proxy-service-name.
-S, --show-error
When used with -s, --silent, it makes curl show an error message
if it fails.
This option is global and does not need to be specified for each
use of --next.
Providing -S, --show-error multiple times has no extra effect.
Disable it again with --no-show-error.
Example:
curl --show-error --silent https://example.com
See also --no-progress-meter.
-s, --silent
Silent or quiet mode. Do not show progress meter or error mes‐
sages. Makes Curl mute. It still outputs the data you ask for,
potentially even to the terminal/stdout unless you redirect it.
Use -S, --show-error in addition to this option to disable
progress meter but still show error messages.
Providing -s, --silent multiple times has no extra effect. Dis‐
able it again with --no-silent.
Example:
curl -s https://example.com
See also -v, --verbose, --stderr and --no-progress-meter.
--socks4 <host[:port]>
Use the specified SOCKS4 proxy. If the port number is not speci‐
fied, it is assumed at port 1080. Using this socket type make
curl resolve the host name and passing the address on to the
proxy.
To specify proxy on a unix domain socket, use localhost for
host, e.g. socks4://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they
are mutually exclusive.
This option is superfluous since you can specify a socks4 proxy
with -x, --proxy using a socks4:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time
proxy is used with an HTTP/HTTPS proxy (added in 7.52.0). In
such a case, curl first connects to the SOCKS proxy and then
connects (through SOCKS) to the HTTP or HTTPS proxy.
If --socks4 is provided several times, the last set value is
used.
Example:
curl --socks4 hostname:4096 https://example.com
See also --socks4a, --socks5 and --socks5-hostname.
--socks4a <host[:port]>
Use the specified SOCKS4a proxy. If the port number is not spec‐
ified, it is assumed at port 1080. This asks the proxy to re‐
solve the host name.
To specify proxy on a unix domain socket, use localhost for
host, e.g. socks4a://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they
are mutually exclusive.
This option is superfluous since you can specify a socks4a proxy
with -x, --proxy using a socks4a:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time
-x, --proxy is used with an HTTP/HTTPS proxy (added in 7.52.0).
In such a case, curl first connects to the SOCKS proxy and then
connects (through SOCKS) to the HTTP or HTTPS proxy.
If --socks4a is provided several times, the last set value is
used.
Example:
curl --socks4a hostname:4096 https://example.com
See also --socks4, --socks5 and --socks5-hostname.
--socks5-basic
Tells curl to use username/password authentication when connect‐
ing to a SOCKS5 proxy. The username/password authentication is
enabled by default. Use --socks5-gssapi to force GSS-API au‐
thentication to SOCKS5 proxies.
Providing --socks5-basic multiple times has no extra effect.
Example:
curl --socks5-basic --socks5 hostname:4096 https://example.com
See also --socks5. Added in 7.55.0.
--socks5-gssapi-nec
As part of the GSS-API negotiation a protection mode is negoti‐
ated. RFC 1961 says in section 4.3/4.4 it should be protected,
but the NEC reference implementation does not. The option
--socks5-gssapi-nec allows the unprotected exchange of the pro‐
tection mode negotiation.
Providing --socks5-gssapi-nec multiple times has no extra ef‐
fect. Disable it again with --no-socks5-gssapi-nec.
Example:
curl --socks5-gssapi-nec --socks5 hostname:4096 https://example.com
See also --socks5.
--socks5-gssapi-service <name>
The default service name for a socks server is rcmd/server-fqdn.
This option allows you to change it.
If --socks5-gssapi-service is provided several times, the last
set value is used.
Example:
curl --socks5-gssapi-service sockd --socks5 hostname:4096 https://example.com
See also --socks5.
--socks5-gssapi
Tells curl to use GSS-API authentication when connecting to a
SOCKS5 proxy. The GSS-API authentication is enabled by default
(if curl is compiled with GSS-API support). Use --socks5-basic
to force username/password authentication to SOCKS5 proxies.
Providing --socks5-gssapi multiple times has no extra effect.
Disable it again with --no-socks5-gssapi.
Example:
curl --socks5-gssapi --socks5 hostname:4096 https://example.com
See also --socks5. Added in 7.55.0.
--socks5-hostname <host[:port]>
Use the specified SOCKS5 proxy (and let the proxy resolve the
host name). If the port number is not specified, it is assumed
at port 1080.
To specify proxy on a unix domain socket, use localhost for
host, e.g. socks5h://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they
are mutually exclusive.
This option is superfluous since you can specify a socks5 host‐
name proxy with -x, --proxy using a socks5h:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time
-x, --proxy is used with an HTTP/HTTPS proxy (added in 7.52.0).
In such a case, curl first connects to the SOCKS proxy and then
connects (through SOCKS) to the HTTP or HTTPS proxy.
If --socks5-hostname is provided several times, the last set
value is used.
Example:
curl --socks5-hostname proxy.example:7000 https://example.com
See also --socks5 and --socks4a.
--socks5 <host[:port]>
Use the specified SOCKS5 proxy - but resolve the host name lo‐
cally. If the port number is not specified, it is assumed at
port 1080.
To specify proxy on a unix domain socket, use localhost for
host, e.g. socks5://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they
are mutually exclusive.
This option is superfluous since you can specify a socks5 proxy
with -x, --proxy using a socks5:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time
-x, --proxy is used with an HTTP/HTTPS proxy (added in 7.52.0).
In such a case, curl first connects to the SOCKS proxy and then
connects (through SOCKS) to the HTTP or HTTPS proxy.
This option (as well as --socks4) does not work with IPV6, FTPS
or LDAP.
If --socks5 is provided several times, the last set value is
used.
Example:
curl --socks5 proxy.example:7000 https://example.com
See also --socks5-hostname and --socks4a.
-Y, --speed-limit <speed>
If a transfer is slower than this given speed (in bytes per sec‐
ond) for speed-time seconds it gets aborted. speed-time is set
with -y, --speed-time and is 30 if not set.
If -Y, --speed-limit is provided several times, the last set
value is used.
Example:
curl --speed-limit 300 --speed-time 10 https://example.com
See also -y, --speed-time, --limit-rate and -m, --max-time.
-y, --speed-time <seconds>
If a transfer runs slower than speed-limit bytes per second dur‐
ing a speed-time period, the transfer is aborted. If speed-time
is used, the default speed-limit is 1 unless set with -Y,
--speed-limit.
This option controls transfers (in both directions) but does not
affect slow connects etc. If this is a concern for you, try the
--connect-timeout option.
If -y, --speed-time is provided several times, the last set
value is used.
Example:
curl --speed-limit 300 --speed-time 10 https://example.com
See also -Y, --speed-limit and --limit-rate.
--ssl-allow-beast
This option tells curl to not work around a security flaw in the
SSL3 and TLS1.0 protocols known as BEAST. If this option is not
used, the SSL layer may use workarounds known to cause interop‐
erability problems with some older SSL implementations.
WARNING: this option loosens the SSL security, and by using this
flag you ask for exactly that.
Providing --ssl-allow-beast multiple times has no extra effect.
Disable it again with --no-ssl-allow-beast.
Example:
curl --ssl-allow-beast https://example.com
See also --proxy-ssl-allow-beast and -k, --insecure.
--ssl-auto-client-cert
(Schannel) Tell libcurl to automatically locate and use a client
certificate for authentication, when requested by the server.
Since the server can request any certificate that supports
client authentication in the OS certificate store it could be a
privacy violation and unexpected.
Providing --ssl-auto-client-cert multiple times has no extra ef‐
fect. Disable it again with --no-ssl-auto-client-cert.
Example:
curl --ssl-auto-client-cert https://example.com
See also --proxy-ssl-auto-client-cert. Added in 7.77.0.
--ssl-no-revoke
(Schannel) This option tells curl to disable certificate revoca‐
tion checks. WARNING: this option loosens the SSL security, and
by using this flag you ask for exactly that.
Providing --ssl-no-revoke multiple times has no extra effect.
Disable it again with --no-ssl-no-revoke.
Example:
curl --ssl-no-revoke https://example.com
See also --crlfile.
--ssl-reqd
(FTP IMAP POP3 SMTP LDAP) Require SSL/TLS for the connection.
Terminates the connection if the transfer cannot be upgraded to
use SSL/TLS.
This option is handled in LDAP (added in 7.81.0). It is fully
supported by the OpenLDAP backend and rejected by the generic
ldap backend if explicit TLS is required.
This option is unnecessary if you use a URL scheme that in it‐
self implies immediate and implicit use of TLS, like for FTPS,
IMAPS, POP3S, SMTPS and LDAPS. Such a transfer always fails if
the TLS handshake does not work.
This option was formerly known as --ftp-ssl-reqd.
Providing --ssl-reqd multiple times has no extra effect. Dis‐
able it again with --no-ssl-reqd.
Example:
curl --ssl-reqd ftp://example.com
See also --ssl and -k, --insecure.
--ssl-revoke-best-effort
(Schannel) This option tells curl to ignore certificate revoca‐
tion checks when they failed due to missing/offline distribution
points for the revocation check lists.
Providing --ssl-revoke-best-effort multiple times has no extra
effect. Disable it again with --no-ssl-revoke-best-effort.
Example:
curl --ssl-revoke-best-effort https://example.com
See also --crlfile and -k, --insecure. Added in 7.70.0.
--ssl (FTP IMAP POP3 SMTP LDAP) Warning: this is considered an inse‐
cure option. Consider using --ssl-reqd instead to be sure curl
upgrades to a secure connection.
Try to use SSL/TLS for the connection. Reverts to a non-secure
connection if the server does not support SSL/TLS. See also
--ftp-ssl-control and --ssl-reqd for different levels of encryp‐
tion required.
This option is handled in LDAP (added in 7.81.0). It is fully
supported by the OpenLDAP backend and ignored by the generic
ldap backend.
Please note that a server may close the connection if the nego‐
tiation does not succeed.
This option was formerly known as --ftp-ssl. That option name
can still be used but might be removed in a future version.
Providing --ssl multiple times has no extra effect. Disable it
again with --no-ssl.
Example:
curl --ssl pop3://example.com/
See also --ssl-reqd, -k, --insecure and --ciphers.
-2, --sslv2
(SSL) This option previously asked curl to use SSLv2, but is now
ignored (added in 7.77.0). SSLv2 is widely considered insecure
(see RFC 6176).
Providing -2, --sslv2 multiple times has no extra effect.
Example:
curl --sslv2 https://example.com
See also --http1.1 and --http2. -2, --sslv2 requires that the
underlying libcurl was built to support TLS. This option is mu‐
tually exclusive to -3, --sslv3 and -1, --tlsv1 and --tlsv1.1
and --tlsv1.2.
-3, --sslv3
(SSL) This option previously asked curl to use SSLv3, but is now
ignored (added in 7.77.0). SSLv3 is widely considered insecure
(see RFC 7568).
Providing -3, --sslv3 multiple times has no extra effect.
Example:
curl --sslv3 https://example.com
See also --http1.1 and --http2. -3, --sslv3 requires that the
underlying libcurl was built to support TLS. This option is mu‐
tually exclusive to -2, --sslv2 and -1, --tlsv1 and --tlsv1.1
and --tlsv1.2.
--stderr <file>
Redirect all writes to stderr to the specified file instead. If
the file name is a plain '-', it is instead written to stdout.
This option is global and does not need to be specified for each
use of --next.
If --stderr is provided several times, the last set value is
used.
Example:
curl --stderr output.txt https://example.com
See also -v, --verbose and -s, --silent.
--styled-output
Enables the automatic use of bold font styles when writing HTTP
headers to the terminal. Use --no-styled-output to switch them
off.
Styled output requires a terminal that supports bold fonts. This
feature is not present on curl for Windows due to lack of this
capability.
This option is global and does not need to be specified for each
use of --next.
Providing --styled-output multiple times has no extra effect.
Disable it again with --no-styled-output.
Example:
curl --styled-output -I https://example.com
See also -I, --head and -v, --verbose. Added in 7.61.0.
--suppress-connect-headers
When -p, --proxytunnel is used and a CONNECT request is made do
not output proxy CONNECT response headers. This option is meant
to be used with -D, --dump-header or -i, --include which are
used to show protocol headers in the output. It has no effect on
debug options such as -v, --verbose or --trace, or any statis‐
tics.
Providing --suppress-connect-headers multiple times has no extra
effect. Disable it again with --no-suppress-connect-headers.
Example:
curl --suppress-connect-headers --include -x proxy https://example.com
See also -D, --dump-header, -i, --include and -p, --proxytunnel.
Added in 7.54.0.
--tcp-fastopen
Enable use of TCP Fast Open (RFC 7413). TCP Fast Open is a TCP
extension that allows data to get sent earlier over the connec‐
tion (before the final handshake ACK) if the client and server
have been connected previously.
Providing --tcp-fastopen multiple times has no extra effect.
Disable it again with --no-tcp-fastopen.
Example:
curl --tcp-fastopen https://example.com
See also --false-start.
--tcp-nodelay
Turn on the TCP_NODELAY option. See the curl_easy_setopt(3) man
page for details about this option.
curl sets this option by default and you need to explicitly
switch it off if you do not want it on (added in 7.50.2).
Providing --tcp-nodelay multiple times has no extra effect.
Disable it again with --no-tcp-nodelay.
Example:
curl --tcp-nodelay https://example.com
See also -N, --no-buffer.
-t, --telnet-option <opt=val>
Pass options to the telnet protocol. Supported options are:
TTYPE=<term> Sets the terminal type.
XDISPLOC=<X display> Sets the X display location.
NEW_ENV=<var,val> Sets an environment variable.
-t, --telnet-option can be used several times in a command line
Example:
curl -t TTYPE=vt100 telnet://example.com/
See also -K, --config.
--tftp-blksize <value>
(TFTP) Set the TFTP BLKSIZE option (must be >512). This is the
block size that curl tries to use when transferring data to or
from a TFTP server. By default 512 bytes are used.
If --tftp-blksize is provided several times, the last set value
is used.
Example:
curl --tftp-blksize 1024 tftp://example.com/file
See also --tftp-no-options.
--tftp-no-options
(TFTP) Tells curl not to send TFTP options requests.
This option improves interop with some legacy servers that do
not acknowledge or properly implement TFTP options. When this
option is used --tftp-blksize is ignored.
Providing --tftp-no-options multiple times has no extra effect.
Disable it again with --no-tftp-no-options.
Example:
curl --tftp-no-options tftp://192.168.0.1/
See also --tftp-blksize.
-z, --time-cond <time>
(HTTP FTP) Request a file that has been modified later than the
given time and date, or one that has been modified before that
time. The <date expression> can be all sorts of date strings or
if it does not match any internal ones, it is taken as a file‐
name and tries to get the modification date (mtime) from <file>
instead. See the curl_getdate(3) man pages for date expression
details.
Start the date expression with a dash (-) to make it request for
a document that is older than the given date/time, default is a
document that is newer than the specified date/time.
If provided a non-existing file, curl outputs a warning about
that fact and proceeds to do the transfer without a time condi‐
tion.
If -z, --time-cond is provided several times, the last set value
is used.
Examples:
curl -z "Wed 01 Sep 2021 12:18:00" https://example.com
curl -z "-Wed 01 Sep 2021 12:18:00" https://example.com
curl -z file https://example.com
See also --etag-compare and -R, --remote-time.
--tls-max <VERSION>
(TLS) VERSION defines maximum supported TLS version. The minimum
acceptable version is set by tlsv1.0, tlsv1.1, tlsv1.2 or
tlsv1.3.
If the connection is done without TLS, this option has no ef‐
fect. This includes QUIC-using (HTTP/3) transfers.
default
Use up to recommended TLS version.
1.0 Use up to TLSv1.0.
1.1 Use up to TLSv1.1.
1.2 Use up to TLSv1.2.
1.3 Use up to TLSv1.3.
If --tls-max is provided several times, the last set value is
used.
Examples:
curl --tls-max 1.2 https://example.com
curl --tls-max 1.3 --tlsv1.2 https://example.com
See also --tlsv1.0, --tlsv1.1, --tlsv1.2 and --tlsv1.3.
--tls-max requires that the underlying libcurl was built to sup‐
port TLS. Added in 7.54.0.
--tls13-ciphers <ciphersuite list>
(TLS) Specifies which cipher suites to use in the connection if
it negotiates TLS 1.3. The list of ciphers suites must specify
valid ciphers. Read up on TLS 1.3 cipher suite details on this
URL:
https://curl.se/docs/ssl-ciphers.html
This option is currently used only when curl is built to use
OpenSSL 1.1.1 or later, or Schannel. If you are using a differ‐
ent SSL backend you can try setting TLS 1.3 cipher suites by us‐
ing the --ciphers option.
If --tls13-ciphers is provided several times, the last set value
is used.
Example:
curl --tls13-ciphers TLS_AES_128_GCM_SHA256 https://example.com
See also --ciphers, --curves and --proxy-tls13-ciphers. Added in
7.61.0.
--tlsauthtype <type>
Set TLS authentication type. Currently, the only supported op‐
tion is "SRP", for TLS-SRP (RFC 5054). If --tlsuser and
--tlspassword are specified but --tlsauthtype is not, then this
option defaults to "SRP". This option works only if the underly‐
ing libcurl is built with TLS-SRP support, which requires
OpenSSL or GnuTLS with TLS-SRP support.
If --tlsauthtype is provided several times, the last set value
is used.
Example:
curl --tlsauthtype SRP https://example.com
See also --tlsuser.
--tlspassword <string>
Set password for use with the TLS authentication method speci‐
fied with --tlsauthtype. Requires that --tlsuser also be set.
This option does not work with TLS 1.3.
If --tlspassword is provided several times, the last set value
is used.
Example:
curl --tlspassword pwd --tlsuser user https://example.com
See also --tlsuser.
--tlsuser <name>
Set username for use with the TLS authentication method speci‐
fied with --tlsauthtype. Requires that --tlspassword also is
set.
This option does not work with TLS 1.3.
If --tlsuser is provided several times, the last set value is
used.
Example:
curl --tlspassword pwd --tlsuser user https://example.com
See also --tlspassword.
--tlsv1.0
(TLS) Forces curl to use TLS version 1.0 or later when connect‐
ing to a remote TLS server.
In old versions of curl this option was documented to allow
_only_ TLS 1.0. That behavior was inconsistent depending on the
TLS library. Use --tls-max if you want to set a maximum TLS ver‐
sion.
Providing --tlsv1.0 multiple times has no extra effect.
Example:
curl --tlsv1.0 https://example.com
See also --tlsv1.3.
--tlsv1.1
(TLS) Forces curl to use TLS version 1.1 or later when connect‐
ing to a remote TLS server.
In old versions of curl this option was documented to allow
_only_ TLS 1.1. That behavior was inconsistent depending on the
TLS library. Use --tls-max if you want to set a maximum TLS ver‐
sion.
Providing --tlsv1.1 multiple times has no extra effect.
Example:
curl --tlsv1.1 https://example.com
See also --tlsv1.3 and --tls-max.
--tlsv1.2
(TLS) Forces curl to use TLS version 1.2 or later when connect‐
ing to a remote TLS server.
In old versions of curl this option was documented to allow
_only_ TLS 1.2. That behavior was inconsistent depending on the
TLS library. Use --tls-max if you want to set a maximum TLS ver‐
sion.
Providing --tlsv1.2 multiple times has no extra effect.
Example:
curl --tlsv1.2 https://example.com
See also --tlsv1.3 and --tls-max.
--tlsv1.3
(TLS) Forces curl to use TLS version 1.3 or later when connect‐
ing to a remote TLS server.
If the connection is done without TLS, this option has no ef‐
fect. This includes QUIC-using (HTTP/3) transfers.
Note that TLS 1.3 is not supported by all TLS backends.
Providing --tlsv1.3 multiple times has no extra effect.
Example:
curl --tlsv1.3 https://example.com
See also --tlsv1.2 and --tls-max. Added in 7.52.0.
-1, --tlsv1
(TLS) Tells curl to use at least TLS version 1.x when negotiat‐
ing with a remote TLS server. That means TLS version 1.0 or
higher
Providing -1, --tlsv1 multiple times has no extra effect.
Example:
curl --tlsv1 https://example.com
See also --http1.1 and --http2. -1, --tlsv1 requires that the
underlying libcurl was built to support TLS. This option is mu‐
tually exclusive to --tlsv1.1 and --tlsv1.2 and --tlsv1.3.
--tr-encoding
(HTTP) Request a compressed Transfer-Encoding response using one
of the algorithms curl supports, and uncompress the data while
receiving it.
Providing --tr-encoding multiple times has no extra effect.
Disable it again with --no-tr-encoding.
Example:
curl --tr-encoding https://example.com
See also --compressed.
--trace-ascii <file>
Enables a full trace dump of all incoming and outgoing data, in‐
cluding descriptive information, to the given output file. Use
"-" as filename to have the output sent to stdout.
This is similar to --trace, but leaves out the hex part and only
shows the ASCII part of the dump. It makes smaller output that
might be easier to read for untrained humans.
Note that verbose output of curl activities and network traffic
might contain sensitive data, including user names, credentials
or secret data content. Be aware and be careful when sharing
trace logs with others.
This option is global and does not need to be specified for each
use of --next.
If --trace-ascii is provided several times, the last set value
is used.
Example:
curl --trace-ascii log.txt https://example.com
See also -v, --verbose and --trace. This option is mutually ex‐
clusive to --trace and -v, --verbose.
--trace-config <string>
Set configuration for trace output. A comma-separated list of
components where detailed output can be made available from.
Names are case-insensitive. Specify 'all' to enable all trace
components.
In addition to trace component names, specify "ids" and "time"
to avoid extra --trace-ids or --trace-time parameters.
See the curl_global_trace(3) man page for more details.
This option is global and does not need to be specified for each
use of --next.
--trace-config can be used several times in a command line
Example:
curl --trace-config ids,http/2 https://example.com
See also -v, --verbose and --trace. This option is mutually ex‐
clusive to --trace and -v, --verbose. Added in 8.3.0.
--trace-ids
Prepends the transfer and connection identifiers to each trace
or verbose line that curl displays.
This option is global and does not need to be specified for each
use of --next.
Providing --trace-ids multiple times has no extra effect. Dis‐
able it again with --no-trace-ids.
Example:
curl --trace-ids --trace-ascii output https://example.com
See also --trace and -v, --verbose. Added in 8.2.0.
--trace-time
Prepends a time stamp to each trace or verbose line that curl
displays.
This option is global and does not need to be specified for each
use of --next.
Providing --trace-time multiple times has no extra effect. Dis‐
able it again with --no-trace-time.
Example:
curl --trace-time --trace-ascii output https://example.com
See also --trace and -v, --verbose.
--trace <file>
Enables a full trace dump of all incoming and outgoing data, in‐
cluding descriptive information, to the given output file. Use
"-" as filename to have the output sent to stdout. Use "%" as
filename to have the output sent to stderr.
Note that verbose output of curl activities and network traffic
might contain sensitive data, including user names, credentials
or secret data content. Be aware and be careful when sharing
trace logs with others.
This option is global and does not need to be specified for each
use of --next.
If --trace is provided several times, the last set value is
used.
Example:
curl --trace log.txt https://example.com
See also --trace-ascii, --trace-config, --trace-ids and
--trace-time. This option is mutually exclusive to -v, --verbose
and --trace-ascii.
--unix-socket <path>
(HTTP) Connect through this Unix domain socket, instead of using
the network.
If --unix-socket is provided several times, the last set value
is used.
Example:
curl --unix-socket socket-path https://example.com
See also --abstract-unix-socket.
-T, --upload-file <file>
This transfers the specified local file to the remote URL.
If there is no file part in the specified URL, curl appends the
local file name to the end of the URL before the operation
starts. You must use a trailing slash (/) on the last directory
to prove to curl that there is no file name or curl thinks that
your last directory name is the remote file name to use.
When putting the local file name at the end of the URL, curl ig‐
nores what is on the left side of any slash (/) or backslash (\)
used in the file name and only appends what is on the right side
of the rightmost such character.
Use the file name "-" (a single dash) to use stdin instead of a
given file. Alternately, the file name "." (a single period)
may be specified instead of "-" to use stdin in non-blocking
mode to allow reading server output while stdin is being up‐
loaded.
If this option is used with a HTTP(S) URL, the PUT method is
used.
You can specify one -T, --upload-file for each URL on the com‐
mand line. Each -T, --upload-file + URL pair specifies what to
upload and to where. curl also supports "globbing" of the -T,
--upload-file argument, meaning that you can upload multiple
files to a single URL by using the same URL globbing style sup‐
ported in the URL.
When uploading to an SMTP server: the uploaded data is assumed
to be RFC 5322 formatted. It has to feature the necessary set of
headers and mail body formatted correctly by the user as curl
does not transcode nor encode it further in any way.
-T, --upload-file can be used several times in a command line
Examples:
curl -T file https://example.com
curl -T "img[1-1000].png" ftp://ftp.example.com/
curl --upload-file "{file1,file2}" https://example.com
See also -G, --get, -I, --head, -X, --request and -d, --data.
--url-query <data>
(all) This option adds a piece of data, usually a name + value
pair, to the end of the URL query part. The syntax is identical
to that used for --data-urlencode with one extension:
If the argument starts with a '+' (plus), the rest of the string
is provided as-is unencoded.
The query part of a URL is the one following the question mark
on the right end.
--url-query can be used several times in a command line
Examples:
curl --url-query name=val https://example.com
curl --url-query =encodethis http://example.net/foo
curl --url-query name@file https://example.com
curl --url-query @fileonly https://example.com
curl --url-query "+name=%20foo" https://example.com
See also --data-urlencode and -G, --get. Added in 7.87.0.
--url <url>
Specify a URL to fetch. This option is mostly handy when you
want to specify URL(s) in a config file.
If the given URL is missing a scheme name (such as "http://" or
"ftp://" etc) then curl makes a guess based on the host. If the
outermost subdomain name matches DICT, FTP, IMAP, LDAP, POP3 or
SMTP then that protocol is used, otherwise HTTP is used. Guess‐
ing can be avoided by providing a full URL including the scheme,
or disabled by setting a default protocol (added in 7.45.0), see
--proto-default for details.
To control where this URL is written, use the -o, --output or
the -O, --remote-name options.
WARNING: On Windows, particular file:// accesses can be con‐
verted to network accesses by the operating system. Beware!
--url can be used several times in a command line
Example:
curl --url https://example.com
See also -:, --next and -K, --config.
-B, --use-ascii
(FTP LDAP) Enable ASCII transfer. For FTP, this can also be en‐
forced by using a URL that ends with ";type=A". This option
causes data sent to stdout to be in text mode for win32 systems.
Providing -B, --use-ascii multiple times has no extra effect.
Disable it again with --no-use-ascii.
Example:
curl -B ftp://example.com/README
See also --crlf and --data-ascii.
-A, --user-agent <name>
(HTTP) Specify the User-Agent string to send to the HTTP server.
To encode blanks in the string, surround the string with single
quote marks. This header can also be set with the -H, --header
or the --proxy-header options.
If you give an empty argument to -A, --user-agent (""), it re‐
moves the header completely from the request. If you prefer a
blank header, you can set it to a single space (" ").
If -A, --user-agent is provided several times, the last set
value is used.
Example:
curl -A "Agent 007" https://example.com
See also -H, --header and --proxy-header.
-u, --user <user:password>
Specify the user name and password to use for server authentica‐
tion. Overrides -n, --netrc and --netrc-optional.
If you simply specify the user name, curl prompts for a pass‐
word.
The user name and passwords are split up on the first colon,
which makes it impossible to use a colon in the user name with
this option. The password can, still.
On systems where it works, curl hides the given option argument
from process listings. This is not enough to protect credentials
from possibly getting seen by other users on the same system as
they still are visible for a brief moment before cleared. Such
sensitive data should be retrieved from a file instead or simi‐
lar and never used in clear text in a command line.
When using Kerberos V5 with a Windows based server you should
include the Windows domain name in the user name, in order for
the server to successfully obtain a Kerberos Ticket. If you do
not, then the initial authentication handshake may fail.
When using NTLM, the user name can be specified simply as the
user name, without the domain, if there is a single domain and
forest in your setup for example.
To specify the domain name use either Down-Level Logon Name or
UPN (User Principal Name) formats. For example, EXAMPLE\user and
[email protected] respectively.
If you use a Windows SSPI-enabled curl binary and perform Ker‐
beros V5, Negotiate, NTLM or Digest authentication then you can
tell curl to select the user name and password from your envi‐
ronment by specifying a single colon with this option: "-u :".
If -u, --user is provided several times, the last set value is
used.
Example:
curl -u user:secret https://example.com
See also -n, --netrc and -K, --config.
--variable <[%]name=text/@file>
Set a variable with "name=content" or "name@file" (where "file"
can be stdin if set to a single dash (-)). The name is a case
sensitive identifier that must consist of no other letters than
a-z, A-Z, 0-9 or underscore. The specified content is then asso‐
ciated with this identifier.
Setting the same variable name again overwrites the old contents
with the new.
The contents of a variable can be referenced in a later command
line option when that option name is prefixed with "--expand-",
and the name is used as "{{name}}" (without the quotes).
--variable can import environment variables into the name space.
Opt to either require the environment variable to be set or pro‐
vide a default value for the variable in case it is not already
set.
--variable %name imports the variable called 'name' but exits
with an error if that environment variable is not already set.
To provide a default value if the environment variable is not
set, use --variable %name=content or --variable %name@content.
Note that on some systems - but not all - environment variables
are case insensitive.
When expanding variables, curl supports a set of functions that
can make the variable contents more convenient to use. You apply
a function to a variable expansion by adding a colon and then
list the desired functions in a comma-separated list that is
evaluated in a left-to-right order. Variable content holding
null bytes that are not encoded when expanded, causes an error.
Available functions:
trim removes all leading and trailing white space.
json outputs the content using JSON string quoting
rules.
url shows the content URL (percent) encoded.
b64 expands the variable base64 encoded
--variable can be used several times in a command line
Example:
curl --variable name=smith https://example.com
See also -K, --config. Added in 8.3.0.
-v, --verbose
Makes curl verbose during the operation. Useful for debugging
and seeing what's going on "under the hood". A line starting
with '>' means "header data" sent by curl, '<' means "header
data" received by curl that is hidden in normal cases, and a
line starting with '*' means additional info provided by curl.
If you only want HTTP headers in the output, -i, --include or
-D, --dump-header might be more suitable options.
If you think this option still does not give you enough details,
consider using --trace or --trace-ascii instead.
Note that verbose output of curl activities and network traffic
might contain sensitive data, including user names, credentials
or secret data content. Be aware and be careful when sharing
trace logs with others.
This option is global and does not need to be specified for each
use of --next.
Providing -v, --verbose multiple times has no extra effect.
Disable it again with --no-verbose.
Example:
curl --verbose https://example.com
See also -i, --include, -s, --silent, --trace and --trace-ascii.
This option is mutually exclusive to --trace and --trace-ascii.
-V, --version
Displays information about curl and the libcurl version it uses.
The first line includes the full version of curl, libcurl and
other 3rd party libraries linked with the executable.
The second line (starts with "Release-Date:") shows the release
date.
The third line (starts with "Protocols:") shows all protocols
that libcurl reports to support.
The fourth line (starts with "Features:") shows specific fea‐
tures libcurl reports to offer. Available features include:
alt-svc
Support for the Alt-Svc: header is provided.
AsynchDNS
This curl uses asynchronous name resolves. Asynchronous
name resolves can be done using either the c-ares or the
threaded resolver backends.
brotli Support for automatic brotli compression over HTTP(S).
CharConv
curl was built with support for character set conversions
(like EBCDIC)
Debug This curl uses a libcurl built with Debug. This enables
more error-tracking and memory debugging etc. For
curl-developers only!
gsasl The built-in SASL authentication includes extensions to
support SCRAM because libcurl was built with libgsasl.
GSS-API
GSS-API is supported.
HSTS HSTS support is present.
HTTP2 HTTP/2 support has been built-in.
HTTP3 HTTP/3 support has been built-in.
HTTPS-proxy
This curl is built to support HTTPS proxy.
IDN This curl supports IDN - international domain names.
IPv6 You can use IPv6 with this.
Kerberos
Kerberos V5 authentication is supported.
Largefile
This curl supports transfers of large files, files larger
than 2GB.
libz Automatic decompression (via gzip, deflate) of compressed
files over HTTP is supported.
MultiSSL
This curl supports multiple TLS backends.
NTLM NTLM authentication is supported.
NTLM_WB
NTLM delegation to winbind helper is supported.
PSL PSL is short for Public Suffix List and means that this
curl has been built with knowledge about "public suf‐
fixes".
SPNEGO SPNEGO authentication is supported.
SSL SSL versions of various protocols are supported, such as
HTTPS, FTPS, POP3S and so on.
SSPI SSPI is supported.
TLS-SRP
SRP (Secure Remote Password) authentication is supported
for TLS.
TrackMemory
Debug memory tracking is supported.
Unicode
Unicode support on Windows.
UnixSockets
Unix sockets support is provided.
zstd Automatic decompression (via zstd) of compressed files
over HTTP is supported.
Example:
curl --version
See also -h, --help and -M, --manual.
-w, --write-out <format>
Make curl display information on stdout after a completed trans‐
fer. The format is a string that may contain plain text mixed
with any number of variables. The format can be specified as a
literal "string", or you can have curl read the format from a
file with "@filename" and to tell curl to read the format from
stdin you write "@-".
The variables present in the output format are substituted by
the value or text that curl thinks fit, as described below. All
variables are specified as %{variable_name} and to output a nor‐
mal % you just write them as %%. You can output a newline by us‐
ing \n, a carriage return with \r and a tab space with \t.
The output is by default written to standard output, but can be
changed with %{stderr} and %output{}.
Output HTTP headers from the most recent request by using
%header{name} where name is the case insensitive name of the
header (without the trailing colon). The header contents are ex‐
actly as sent over the network, with leading and trailing white‐
space trimmed (added in 7.84.0).
Select a specific target destination file to write the output
to, by using %output{name} (added in curl 8.3.0) where name is
the full file name. The output following that instruction is
then written to that file. More than one %output{} instruction
can be specified in the same write-out argument. If the file
name cannot be created, curl leaves the output destination to
the one used prior to the %output{} instruction. Use %out‐
put{>>name} to append data to an existing file.
NOTE: In Windows the %-symbol is a special symbol used to expand
environment variables. In batch files all occurrences of % must
be doubled when using this option to properly escape. If this
option is used at the command prompt then the % cannot be es‐
caped and unintended expansion is possible.
The variables available are:
certs Output the certificate chain with details. Sup‐
ported only by the OpenSSL, GnuTLS, Schannel and
Secure Transport backends. (Added in 7.88.0)
content_type The Content-Type of the requested document, if
there was any.
errormsg The error message. (Added in 7.75.0)
exitcode The numerical exit code of the transfer. (Added
in 7.75.0)
filename_effective
The ultimate filename that curl writes out to.
This is only meaningful if curl is told to write
to a file with the -O, --remote-name or -o,
--output option. It's most useful in combination
with the -J, --remote-header-name option.
ftp_entry_path The initial path curl ended up in when logging on
to the remote FTP server.
header_json A JSON object with all HTTP response headers from
the recent transfer. Values are provided as ar‐
rays, since in the case of multiple headers there
can be multiple values. (Added in 7.83.0)
The header names provided in lowercase, listed in
order of appearance over the wire. Except for du‐
plicated headers. They are grouped on the first
occurrence of that header, each value is pre‐
sented in the JSON array.
http_code The numerical response code that was found in the
last retrieved HTTP(S) or FTP(s) transfer.
http_connect The numerical code that was found in the last re‐
sponse (from a proxy) to a curl CONNECT request.
http_version The http version that was effectively used.
(Added in 7.50.0)
json A JSON object with all available keys. (Added in
7.70.0)
local_ip The IP address of the local end of the most re‐
cently done connection - can be either IPv4 or
IPv6.
local_port The local port number of the most recently done
connection.
method The http method used in the most recent HTTP re‐
quest. (Added in 7.72.0)
num_certs Number of server certificates received in the TLS
handshake. Supported only by the OpenSSL, GnuTLS,
Schannel and Secure Transport backends. (Added
in 7.88.0)
num_connects Number of new connects made in the recent trans‐
fer.
num_headers The number of response headers in the most recent
request (restarted at each redirect). Note that
the status line IS NOT a header. (Added in
7.73.0)
num_redirects Number of redirects that were followed in the re‐
quest.
onerror The rest of the output is only shown if the
transfer returned a non-zero error. (Added in
7.75.0)
proxy_ssl_verify_result
The result of the HTTPS proxy's SSL peer certifi‐
cate verification that was requested. 0 means the
verification was successful. (Added in 7.52.0)
redirect_url When an HTTP request was made without -L, --loca‐
tion to follow redirects (or when --max-redirs is
met), this variable shows the actual URL a redi‐
rect would have gone to.
referer The Referer: header, if there was any. (Added in
7.76.0)
remote_ip The remote IP address of the most recently done
connection - can be either IPv4 or IPv6.
remote_port The remote port number of the most recently done
connection.
response_code The numerical response code that was found in the
last transfer (formerly known as "http_code").
scheme The URL scheme (sometimes called protocol) that
was effectively used. (Added in 7.52.0)
size_download The total amount of bytes that were downloaded.
This is the size of the body/data that was trans‐
ferred, excluding headers.
size_header The total amount of bytes of the downloaded head‐
ers.
size_request The total amount of bytes that were sent in the
HTTP request.
size_upload The total amount of bytes that were uploaded.
This is the size of the body/data that was trans‐
ferred, excluding headers.
speed_download The average download speed that curl measured for
the complete download. Bytes per second.
speed_upload The average upload speed that curl measured for
the complete upload. Bytes per second.
ssl_verify_result
The result of the SSL peer certificate verifica‐
tion that was requested. 0 means the verification
was successful.
stderr From this point on, the -w, --write-out output is
written to standard error. (Added in 7.63.0)
stdout From this point on, the -w, --write-out output is
written to standard output. This is the default,
but can be used to switch back after switching to
stderr. (Added in 7.63.0)
time_appconnect
The time, in seconds, it took from the start un‐
til the SSL/SSH/etc connect/handshake to the re‐
mote host was completed.
time_connect The time, in seconds, it took from the start un‐
til the TCP connect to the remote host (or proxy)
was completed.
time_namelookup
The time, in seconds, it took from the start un‐
til the name resolving was completed.
time_pretransfer
The time, in seconds, it took from the start un‐
til the file transfer was just about to begin.
This includes all pre-transfer commands and nego‐
tiations that are specific to the particular pro‐
tocol(s) involved.
time_redirect The time, in seconds, it took for all redirection
steps including name lookup, connect, pretransfer
and transfer before the final transaction was
started. time_redirect shows the complete execu‐
tion time for multiple redirections.
time_starttransfer
The time, in seconds, it took from the start un‐
til the first byte is received. This includes
time_pretransfer and also the time the server
needed to calculate the result.
time_total The total time, in seconds, that the full opera‐
tion lasted.
url The URL that was fetched. (Added in 7.75.0)
url.scheme The scheme part of the URL that was fetched.
(Added in 8.1.0)
url.user The user part of the URL that was fetched. (Added
in 8.1.0)
url.password The password part of the URL that was fetched.
(Added in 8.1.0)
url.options The options part of the URL that was fetched.
(Added in 8.1.0)
url.host The host part of the URL that was fetched. (Added
in 8.1.0)
url.port The port number of the URL that was fetched. If
no port number was specified, but the URL scheme
is known, that scheme's default port number is
shown. (Added in 8.1.0)
url.path The path part of the URL that was fetched. (Added
in 8.1.0)
url.query The query part of the URL that was fetched.
(Added in 8.1.0)
url.fragment The fragment part of the URL that was fetched.
(Added in 8.1.0)
url.zoneid The zone id part of the URL that was fetched.
(Added in 8.1.0)
urle.scheme The scheme part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.user The user part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.password The password part of the effective (last) URL
that was fetched. (Added in 8.1.0)
urle.options The options part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.host The host part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.port The port number of the effective (last) URL that
was fetched. If no port number was specified, but
the URL scheme is known, that scheme's default
port number is shown. (Added in 8.1.0)
urle.path The path part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.query The query part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.fragment The fragment part of the effective (last) URL
that was fetched. (Added in 8.1.0)
urle.zoneid The zone id part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urlnum The URL index number of this transfer, 0-indexed.
Unglobbed URLs share the same index number as the
origin globbed URL. (Added in 7.75.0)
url_effective The URL that was fetched last. This is most mean‐
ingful if you have told curl to follow location:
headers.
If -w, --write-out is provided several times, the last set value
is used.
Example:
curl -w '%{response_code}\n' https://example.com
See also -v, --verbose and -I, --head.
--xattr
When saving output to a file, this option tells curl to store
certain file metadata in extended file attributes. Currently,
the URL is stored in the xdg.origin.url attribute and, for HTTP,
the content type is stored in the mime_type attribute. If the
file system does not support extended attributes, a warning is
issued.
Providing --xattr multiple times has no extra effect. Disable
it again with --no-xattr.
Example:
curl --xattr -o storage https://example.com
See also -R, --remote-time, -w, --write-out and -v, --verbose.
FILES
~/.curlrc
Default config file, see -K, --config for details.
ENVIRONMENT
The environment variables can be specified in lower case or upper case.
The lower case version has precedence. http_proxy is an exception as it
is only available in lower case.
Using an environment variable to set the proxy has the same effect as
using the -x, --proxy option.
http_proxy [protocol://]<host>[:port]
Sets the proxy server to use for HTTP.
HTTPS_PROXY [protocol://]<host>[:port]
Sets the proxy server to use for HTTPS.
[url-protocol]_PROXY [protocol://]<host>[:port]
Sets the proxy server to use for [url-protocol], where the pro‐
tocol is a protocol that curl supports and as specified in a
URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP, etc.
ALL_PROXY [protocol://]<host>[:port]
Sets the proxy server to use if no protocol-specific proxy is
set.
NO_PROXY <comma-separated list of hosts/domains>
list of host names that should not go through any proxy. If set
to an asterisk '*' only, it matches all hosts. Each name in this
list is matched as either a domain name which contains the host‐
name, or the hostname itself.
This environment variable disables use of the proxy even when
specified with the -x, --proxy option. That is NO_PROXY=di‐
rect.example.com curl -x http://proxy.example.com http://di‐
rect.example.com accesses the target URL directly, and
NO_PROXY=direct.example.com curl -x http://proxy.example.com
http://somewhere.example.com accesses the target URL through the
proxy.
The list of host names can also be include numerical IP ad‐
dresses, and IPv6 versions should then be given without enclos‐
ing brackets.
IP addresses can be specified using CIDR notation: an appended
slash and number specifies the number of "network bits" out of
the address to use in the comparison (added in 7.86.0). For ex‐
ample "192.168.0.0/16" would match all addresses starting with
"192.168".
APPDATA <dir>
On Windows, this variable is used when trying to find the home
directory. If the primary home variable are all unset.
COLUMNS <terminal width>
If set, the specified number of characters is used as the termi‐
nal width when the alternative progress-bar is shown. If not
set, curl tries to figure it out using other ways.
CURL_CA_BUNDLE <file>
If set, it is used as the --cacert value.
CURL_HOME <dir>
If set, is the first variable curl checks when trying to find
its home directory. If not set, it continues to check XDG_CON‐
FIG_HOME
CURL_SSL_BACKEND <TLS backend>
If curl was built with support for "MultiSSL", meaning that it
has built-in support for more than one TLS backend, this envi‐
ronment variable can be set to the case insensitive name of the
particular backend to use when curl is invoked. Setting a name
that is not a built-in alternative makes curl stay with the de‐
fault.
SSL backend names (case-insensitive): bearssl, gnutls, mbedtls,
openssl, rustls, schannel, secure-transport, wolfssl
HOME <dir>
If set, this is used to find the home directory when that is
needed. Like when looking for the default .curlrc. CURL_HOME and
XDG_CONFIG_HOME have preference.
QLOGDIR <directory name>
If curl was built with HTTP/3 support, setting this environment
variable to a local directory makes curl produce qlogs in that
directory, using file names named after the destination connec‐
tion id (in hex). Do note that these files can become rather
large. Works with the ngtcp2 and quiche QUIC backends.
SHELL Used on VMS when trying to detect if using a DCL or a unix
shell.
SSL_CERT_DIR <dir>
If set, it is used as the --capath value.
SSL_CERT_FILE <path>
If set, it is used as the --cacert value.
SSLKEYLOGFILE <file name>
If you set this environment variable to a file name, curl stores
TLS secrets from its connections in that file when invoked to
enable you to analyze the TLS traffic in real time using network
analyzing tools such as Wireshark. This works with the following
TLS backends: OpenSSL, libressl, BoringSSL, GnuTLS and wolfSSL.
USERPROFILE <dir>
On Windows, this variable is used when trying to find the home
directory. If the other, primary, variable are all unset. If
set, curl uses the path "$USERPROFILE\Application Data".
XDG_CONFIG_HOME <dir>
If CURL_HOME is not set, this variable is checked when looking
for a default .curlrc file.
PROXY PROTOCOL PREFIXES
The proxy string may be specified with a protocol:// prefix to specify
alternative proxy protocols.
If no protocol is specified in the proxy string or if the string does
not match a supported one, the proxy is treated as an HTTP proxy.
The supported proxy protocol prefixes are as follows:
http://
Makes it use it as an HTTP proxy. The default if no scheme pre‐
fix is used.
https://
Makes it treated as an HTTPS proxy.
socks4://
Makes it the equivalent of --socks4
socks4a://
Makes it the equivalent of --socks4a
socks5://
Makes it the equivalent of --socks5
socks5h://
Makes it the equivalent of --socks5-hostname
EXIT CODES
There are a bunch of different error codes and their corresponding er‐
ror messages that may appear under error conditions. At the time of
this writing, the exit codes are:
0 Success. The operation completed successfully according to the
instructions.
1 Unsupported protocol. This build of curl has no support for this
protocol.
2 Failed to initialize.
3 URL malformed. The syntax was not correct.
4 A feature or option that was needed to perform the desired re‐
quest was not enabled or was explicitly disabled at build-time.
To make curl able to do this, you probably need another build of
libcurl.
5 Could not resolve proxy. The given proxy host could not be re‐
solved.
6 Could not resolve host. The given remote host could not be re‐
solved.
7 Failed to connect to host.
8 Weird server reply. The server sent data curl could not parse.
9 FTP access denied. The server denied login or denied access to
the particular resource or directory you wanted to reach. Most
often you tried to change to a directory that does not exist on
the server.
10 FTP accept failed. While waiting for the server to connect back
when an active FTP session is used, an error code was sent over
the control connection or similar.
11 FTP weird PASS reply. Curl could not parse the reply sent to the
PASS request.
12 During an active FTP session while waiting for the server to
connect back to curl, the timeout expired.
13 FTP weird PASV reply, Curl could not parse the reply sent to the
PASV request.
14 FTP weird 227 format. Curl could not parse the 227-line the
server sent.
15 FTP cannot use host. Could not resolve the host IP we got in the
227-line.
16 HTTP/2 error. A problem was detected in the HTTP2 framing layer.
This is somewhat generic and can be one out of several problems,
see the error message for details.
17 FTP could not set binary. Could not change transfer method to
binary.
18 Partial file. Only a part of the file was transferred.
19 FTP could not download/access the given file, the RETR (or simi‐
lar) command failed.
21 FTP quote error. A quote command returned error from the server.
22 HTTP page not retrieved. The requested URL was not found or re‐
turned another error with the HTTP error code being 400 or
above. This return code only appears if -f, --fail is used.
23 Write error. Curl could not write data to a local filesystem or
similar.
25 Failed starting the upload. For FTP, the server typically denied
the STOR command.
26 Read error. Various reading problems.
27 Out of memory. A memory allocation request failed.
28 Operation timeout. The specified time-out period was reached ac‐
cording to the conditions.
30 FTP PORT failed. The PORT command failed. Not all FTP servers
support the PORT command, try doing a transfer using PASV in‐
stead!
31 FTP could not use REST. The REST command failed. This command is
used for resumed FTP transfers.
33 HTTP range error. The range "command" did not work.
34 HTTP post error. Internal post-request generation error.
35 SSL connect error. The SSL handshaking failed.
36 Bad download resume. Could not continue an earlier aborted down‐
load.
37 FILE could not read file. Failed to open the file. Permissions?
38 LDAP cannot bind. LDAP bind operation failed.
39 LDAP search failed.
41 Function not found. A required LDAP function was not found.
42 Aborted by callback. An application told curl to abort the oper‐
ation.
43 Internal error. A function was called with a bad parameter.
45 Interface error. A specified outgoing interface could not be
used.
47 Too many redirects. When following redirects, curl hit the maxi‐
mum amount.
48 Unknown option specified to libcurl. This indicates that you
passed a weird option to curl that was passed on to libcurl and
rejected. Read up in the manual!
49 Malformed telnet option.
52 The server did not reply anything, which here is considered an
error.
53 SSL crypto engine not found.
54 Cannot set SSL crypto engine as default.
55 Failed sending network data.
56 Failure in receiving network data.
58 Problem with the local certificate.
59 Could not use specified SSL cipher.
60 Peer certificate cannot be authenticated with known CA certifi‐
cates.
61 Unrecognized transfer encoding.
63 Maximum file size exceeded.
64 Requested FTP SSL level failed.
65 Sending the data requires a rewind that failed.
66 Failed to initialize SSL Engine.
67 The user name, password, or similar was not accepted and curl
failed to log in.
68 File not found on TFTP server.
69 Permission problem on TFTP server.
70 Out of disk space on TFTP server.
71 Illegal TFTP operation.
72 Unknown TFTP transfer ID.
73 File already exists (TFTP).
74 No such user (TFTP).
77 Problem reading the SSL CA cert (path? access rights?).
78 The resource referenced in the URL does not exist.
79 An unspecified error occurred during the SSH session.
80 Failed to shut down the SSL connection.
82 Could not load CRL file, missing or wrong format.
83 Issuer check failed.
84 The FTP PRET command failed.
85 Mismatch of RTSP CSeq numbers.
86 Mismatch of RTSP Session Identifiers.
87 Unable to parse FTP file list.
88 FTP chunk callback reported error.
89 No connection available, the session is queued.
90 SSL public key does not matched pinned public key.
91 Invalid SSL certificate status.
92 Stream error in HTTP/2 framing layer.
93 An API function was called from inside a callback.
94 An authentication function returned an error.
95 A problem was detected in the HTTP/3 layer. This is somewhat
generic and can be one out of several problems, see the error
message for details.
96 QUIC connection error. This error may be caused by an SSL li‐
brary error. QUIC is the protocol used for HTTP/3 transfers.
97 Proxy handshake error.
98 A client-side certificate is required to complete the TLS hand‐
shake.
99 Poll or select returned fatal error.
XX More error codes might appear here in future releases. The ex‐
isting ones are meant to never change.
BUGS
If you experience any problems with curl, submit an issue in the
project's bug tracker on GitHub: https://github.com/curl/curl/issues
AUTHORS / CONTRIBUTORS
Daniel Stenberg is the main author, but the whole list of contributors
is found in the separate THANKS file.
WWW
https://curl.se
SEE ALSO
ftp(1), wget(1)
curl 8.5.0 December 05 2023 curl(1)