Print the full filename of the current working directory.打印当前工作目录
-L, --logical
use PWD from environment, even if it contains symlinks # 显示当前路径包括link路径
-P, --physical # 显示当前路径而非使用link路径
avoid all symlinks
Create the DIRECTORY(ies), if they do not already exist.
Mandatory arguments to long options are mandatory for short options
too.
-m, --mode=MODE #配置文件的权限。直接设置，不需要看默认权限
set file mode (as in chmod), not a=rwx - umask
-p, --parents
no error if existing, make parent directories as needed
-v, --verbose
print a message for each created directory
原文：http://www.cnblogs.com/wenyule/p/7620560.html