#Bash 的 which 命令

which [OPTION]... NAME...

功能

在 PATH 环境变量中定位命令的位置。

类型

可执行文件（/usr/bin/which），属于 which。

参数

OPTION 选项：
- -a - 打印所有匹配的路径；而非第一个匹配的路径
- -s - 不打印任何内容，仅通过返回值报告是否找到
NAME - 要定位的命令列表

返回值

0 - 所有命令都找到且可执行
1 - 存在命令找不到或不可执行
2 - 指定了无效的选项参数

#示例

$ which ls           # 在 PATH 中查找 ls
/usr/bin/ls
$ which ls cat       # 在 PATH 中查找 ls 和 cat
/usr/bin/ls
/usr/bin/cat
$ which -a ls cat    # 打印所有匹配的路径
/usr/bin/ls
/bin/ls
/usr/bin/cat
/bin/cat

#相关命令

命令	说明
whereis	定位二进制文件、源码文件和手册文件

#推荐阅读

which(1) — Linux manual page

#手册

WHICH(1)                    General Commands Manual                   WHICH(1)

NAME
       which - locate a command

SYNOPSIS
       which [-as] filename ...

DESCRIPTION
       which returns the pathnames of the files (or links) which would be exe‐
       cuted  in the current environment, had its arguments been given as com‐
       mands in a strictly POSIX-conformant shell.  It does this by  searching
       the  PATH for executable files matching the names of the arguments.  It
       does not canonicalize path names.

OPTIONS
       -a     print all matching pathnames of each argument

       -s     silently return 0 if all of the executables were found or 1 oth‐
              erwise

EXIT STATUS
       0      if all specified commands are found and executable

       1      if one or more specified commands is  nonexistent  or  not  exe‐
              cutable

       2      if an invalid option is specified

Debian                            29 Jun 2016                         WHICH(1)

#Bash 的 which 命令

#示例

#相关命令

#推荐阅读

#手册

显示