Creates a temporary directory. See the mkdtemp() documentation on most UNIX-like systems.
The parameter is a string that should follow the rules for mkdtemp() templates, i.e. contain the string "XXXXXX". g_mkdtemp_full() is slightly more flexible than mkdtemp() in that the sequence does not have to occur at the very end of the template and you can pass a mode. The X string will be modified to form the name of a directory that didn't exist. The string should be in the GLib file name encoding. Most importantly, on Windows it should be in UTF-8.
If you are going to be creating a temporary directory inside the directory returned by g_get_tmp_dir(), you might want to use g_dir_make_tmp() instead.