#Bash 的 sha256sum 命令

sha256sum [OPTION]... [FILE]...

功能

计算或校验 SHA256 值。

类型

可执行文件（/usr/bin/sha256sum），属于 coreutils。

参数

• OPTION 选项：
  • -b, --binary - 以二进制模式读取文件；类 UNIX 系统下始终是二进制模式
  • -c, --check - 从文件中读取 SHA256 值进行校验
  • --tag- 生成 BSD 风格的输出
  • -t, --text - 以文本模式读取文件；类 UNIX 系统下不存在文本模式，此选项无效
  • -z, --zero - 以空字符（\0）作为行的结尾，而不是换行符（\n）
  • --ignore-missing - 校验时忽略缺失的文件
  • --quiet - 校验时不打印成功的消息
  • --status - 校验时不打印任何消息；可以通过返回值检查是否成功
  • --strict - 校验时严格检查格式
  • -w, --warn - 校验时遇到格式不正确的行时产生警告
  • --help - 显示帮助
  • --version - 显示版本
• FILE - 文件列表

#示例

计算 SHA256 值

$ sha256sum 1.txt                                     # 单个文件
6fc9ba098aa5065ea38f4c9b4eea877685d6150af612b3c1e042dddf9977acda  1.txt
$ sha256sum 1.txt 2.txt 3.txt                         # 多个文件
6fc9ba098aa5065ea38f4c9b4eea877685d6150af612b3c1e042dddf9977acda  1.txt
952be6c3e9b1f3af5d8daf7698bc9b5ba20323738990713839f6f7c236f8fe12  2.txt
a948904f2f0f479b8f8197694b30184b0d2ed1c1cd2a1ec0fb85d299a192a447  3.txt
$ sha256sum --tag 1.txt 2.txt 3.txt                   # BSD 风格
SHA256 (1.txt) = 6fc9ba098aa5065ea38f4c9b4eea877685d6150af612b3c1e042dddf9977acda
SHA256 (2.txt) = 952be6c3e9b1f3af5d8daf7698bc9b5ba20323738990713839f6f7c236f8fe12
SHA256 (3.txt) = a948904f2f0f479b8f8197694b30184b0d2ed1c1cd2a1ec0fb85d299a192a447

校验 SHA256 值

$ sha256sum 1.txt 2.txt 3.txt > sha1.txt
$ sha256sum -c sha1.txt                               # 校验
1.txt: OK
2.txt: OK
3.txt: OK

#相关命令

#推荐阅读

• Print or check SHA-2 digests - GNU Coreutils
• sha256sum(1) — Linux manual page

#手册

显示
SHA256SUM(1)                     User Commands                    SHA256SUM(1)

NAME
       sha256sum - compute and check SHA256 message digest

SYNOPSIS
       sha256sum [OPTION]... [FILE]...

DESCRIPTION
       Print or check SHA256 (256-bit) checksums.

       With no FILE, or when FILE is -, read standard input.

       -b, --binary
              read in binary mode

       -c, --check
              read checksums from the FILEs and check them

       --tag  create a BSD-style checksum

       -t, --text
              read in text mode (default)

       -z, --zero
              end  each  output  line  with NUL, not newline, and disable file
              name escaping

   The following five options are useful only when verifying checksums:
       --ignore-missing
              don't fail or report status for missing files

       --quiet
              don't print OK for each successfully verified file

       --status
              don't output anything, status code shows success

       --strict
              exit non-zero for improperly formatted checksum lines

       -w, --warn
              warn about improperly formatted checksum lines

       --help display this help and exit

       --version
              output version information and exit

       The sums are computed as described in FIPS-180-2.  When  checking,  the
       input  should  be a former output of this program.  The default mode is
       to print a line with: checksum, a space, a character  indicating  input
       mode  ('*'  for binary, ' ' for text or where binary is insignificant),
       and name for each FILE.

       Note: There is no difference between binary mode and text mode  on  GNU
       systems.

AUTHOR
       Written by Ulrich Drepper, Scott Miller, and David Madore.

REPORTING BUGS
       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
       Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT
       Copyright  ©  2023  Free Software Foundation, Inc.  License GPLv3+: GNU
       GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free  to  change  and  redistribute  it.
       There is NO WARRANTY, to the extent permitted by law.

SEE ALSO
       cksum(1)

       Full documentation <https://www.gnu.org/software/coreutils/sha256sum>
       or available locally via: info '(coreutils) sha2 utilities'

GNU coreutils 9.4                 April 2024                      SHA256SUM(1)