#Bash 的 namei 命令

namei [OPTION]... PATH

功能

逐级访问路径并显示其信息。

类型

可执行文件（/usr/bin/namei），属于 util-linux。

参数

OPTION 选项：
- -l, --long - 使用长格式输出；等价于 -m -o -v
- -m, --modes - 打印文件权限
- -n, --nosymlinks - 不跟随符号链接
- -o, --owners - 打印文件的所有者
- -v, --vertical - 垂直对齐
- -x, --mountpoints - 作为挂载点的目录显示为 D 而不是 d
- -Z, --context - 显示安全上下文
- -h, --help - 显示帮助
- -V, --version - 显示版本
FILE - 要判断的文件

#文件类型标识

f: - 正在解析的路径
d - 目录
l - 符号链接
s - socket
b - 块设备
c - 字符设备
p - FIFO (命名管道)
- - 普通文件
? - 错误

#示例

检查路径错误的具体位置

$ namei /home/user1/dir/file        # 检查 /home/user1/dir/file
f: /var/www/html/dasdaxasds
 d /
 d home
 d user1
    dir - No such file or directory

检查权限错误的具体位置

$ namei /home/user2/dir/file        # 检查 /home/user2/dir/file
f: /home/user2/dir/file
 d /
 d home
 d user2
    dir - Permission denied

调试 Web 服务访问失败的原因

$ sudo -u www-data namei /var/www/html/index.html   # 以 www-data 用户的权限检查 /var/www/html/index.html
f: /var/www/html/index.html
 d /
 d var
 d www
    html - Permission denied

#推荐阅读

namei(1) — Linux manual page

#手册

NAMEI(1)                         User Commands                        NAMEI(1)

NAME
       namei - follow a pathname until a terminal point is found

SYNOPSIS
       namei [options] pathname...

DESCRIPTION
       namei interprets its arguments as pathnames to any type of Unix file
       (symlinks, files, directories, and so forth). namei then follows each
       pathname until an endpoint is found (a file, a directory, a device
       node, etc). If it finds a symbolic link, it shows the link, and starts
       following it, indenting the output to show the context.

       This program is useful for finding "too many levels of symbolic links"
       problems.

       For each line of output, namei uses the following characters to
       identify the file type found:

              f: = the pathname currently being resolved
               d = directory
               l = symbolic link (both the link and its contents are output)
               s = socket
               b = block device
               c = character device
               p = FIFO (named pipe)
               - = regular file
               ? = an error of some kind

       namei prints an informative message when the maximum number of symbolic
       links this system can have has been exceeded.

OPTIONS
       -l, --long
           Use the long listing format (same as -m -o -v).

       -m, --modes
           Show the mode bits of each file type in the style of ls(1), for
           example 'rwxr-xr-x'.

       -n, --nosymlinks
           Don’t follow symlinks.

       -o, --owners
           Show owner and group name of each file.

       -v, --vertical
           Vertically align the modes and owners.

       -x, --mountpoints
           Show mountpoint directories with a 'D' rather than a 'd'.

       -Z, --context
           Show security context of the file or "?" if not available. The
           support for security contexts is optional and does not have to be
           compiled to the namei binary.

       -h, --help
           Display help text and exit.

       -V, --version
           Print version and exit.

BUGS
       To be discovered.

AUTHORS
       The original namei program was written by Roger Southwick
       <rogers@amadeus.wr.tek.com>.

       The program was rewritten by Karel Zak Karel Zak <kzak@redhat.com>.

SEE ALSO
       ls(1), stat(1), symlink(7)

REPORTING BUGS
       For bug reports, use the issue tracker at
       https://github.com/util-linux/util-linux/issues.

AVAILABILITY
       The namei command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.39.3                 2023-11-21                          NAMEI(1)