What is the verbose option in mkdir?

From the source code for mkdir.c, this is the section that deals with the -v option:

    case 'v': /* --verbose  */      options.created_directory_format = _("created directory %s");      break;

As you can see, the string that is used is hard-coded into the source. To permanently change the message to a custom message, one can modify this section of the source code and recompile mkdir.

You can create a script like this:

#/bin/bash/bin/mkdir "$@" |sed -e"s/mkdir: created directory /$USER created folder /"

Then run that script rather than mkdir.

Modify that script for each message you want to change by adding an additional -e"s/x/y" to the sed.

If you insist on it being named mkdir, then you can put it in your search path before mkdir.

I would not recommend naming it mkdir. You will only cause yourself grief for other scripts that call mkdir

If you are satisfied with a wrapper, try something like

mkdir -v "$@" | sed 's/mkdir: created directory /jar-jar: yea, weesa gotta /'

More fundamentally, the message string in mkdir is usually more or less hard-coded. However, if there is localization support, you could actually override the message catalog with your own.

For example, if your mkdir was built with gettext, you could create a new English .po file, replace the directory creation message, build a new locale, and run with that. See also http://translationproject.org/domain/coreutils.html

Depending on what you want, this is somewhere between severe overkill and insane.