pwd--print name of current/working directory

SYNOPSIS       pwd [OPTION]...DESCRIPTION       Print the full filename of the current working directory.       -L, --logical              use PWD from environment, even if it contains symlinks       -P, --physical              avoid all symlinks       --help display this help and exit       --version              output version information and exit       NOTE:  your shell may have its own version of pwd, which usually super‐       sedes the version described here.  Please refer to your  shell's  docu‐       mentation for details about the options it supports.AUTHOR       Written by Jim Meyering.

-L  选项为逻辑路径

-P 显示绝对路径

Link to book 为~/Documents/book在~/Desktop的链接