Task

Create a directory and any missing parents.

This task is named after the posix mkdir -p command, and several libraries which implement the same behavior.

Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect.
If the directory already exists, return successfully.
Ideally implementations will work equally well cross-platform (on windows, linux, and OS X).

It's likely that your language implements such a function as part of its standard library. If so, please also show how such a function would be implemented.




/*REXX program  creates a  directory (folder)  and all its  parent paths  as necessary. */
trace off                                              /*suppress possible warning msgs.*/
 
dPath = 'path\to\dir'                                  /*define directory (folder) path.*/
 
'MKDIR'  dPath  "2>nul"                                /*alias could be used:  MD dPath */
                                                       /*stick a fork in it, we're done.*/