mkdir - make a directory
mkdir [ -p ] [ -m mode ] dirname ...
Mkdir creates the specified directories. It requires write permission in the parent directory.
If the -p flag is given, mkdir creates any necessary parent directories and does not complain if the target directory already exists.
The -m flag sets the permissions to be used when creating the directory. The default is 0777.
Mkdir returns null exit status if all directories were successfully made. Otherwise it prints a diagnostic and returns error status.