which和whereis

• 系统中常用which和whereis来查找命令的位置
• which比where更直白和简洁的定位到程序的位置
• whereis比which显示的更丰富，可以同时显示帮助及二进制文件

[二 3月 23 23:19:43 root@C8-3-55 ~ ]# which yum
/usr/bin/yum
[二 3月 23 23:49:13 root@C8-3-55 ~ ]# whereis yum
yum: /usr/bin/yum /etc/yum /etc/yum.conf /usr/share/man/man8/yum.8.gz

whereis

[二 3月 23 23:49:21 root@C8-3-55 ~ ]# whereis --help

用法：
 whereis [选项] [-BMS <dir>... -f] <名称>

定位某个命令的二进制文件、源码和帮助页文件。

选项：
 -b         只搜索二进制文件
 -B <目录>  定义二进制文件查找路径
 -m         只搜索手册和信息
 -M <目录>  定义 man 和 info 查找路径
 -s         只搜索源代码
 -S <目录>  定义源代码查找路径
 -f         终止 <目录> 参数列表
 -u         搜索不常见记录
 -l         输出有效查找路径

 -h, --help     display this help
 -V, --version  display version

更多信息请参阅 whereis(1)。

which

[二 3月 23 23:49:50 root@C8-3-55 ~ ]# which --help
Usage: /usr/bin/which [options] [--] COMMAND [...]
Write the full path of COMMAND(s) to standard output.

  --version, -[vV] Print version and exit successfully.
  --help,          Print this help and exit successfully.
  --skip-dot       Skip directories in PATH that start with a dot.
  --skip-tilde     Skip directories in PATH that start with a tilde.
  --show-dot       Don't expand a dot to current directory in output.
  --show-tilde     Output a tilde for HOME directory for non-root.
  --tty-only       Stop processing options on the right if not on tty.
  --all, -a        Print all matches in PATH, not just the first
  --read-alias, -i Read list of aliases from stdin.
  --skip-alias     Ignore option --read-alias; don't read stdin.
  --read-functions Read shell functions from stdin.
  --skip-functions Ignore option --read-functions; don't read stdin.

Recommended use is to write the output of (alias; declare -f) to standard
input, so that which can show aliases and shell functions. See which(1) for
examples.

If the options --read-alias and/or --read-functions are specified then the
output can be a full alias or function definition, optionally followed by
the full path of each command used inside of those.

Report bugs to <which-bugs@gnu.org>.