function generates a uniquely named temporary
directory from template.
The last six characters of template
must be XXXXXX and these are replaced with a string that makes the
directory name unique.
The directory is then created with
Since it will be modified,
must not be a string constant, but should be declared as a character array.
function returns a pointer to the modified template
string on success, and NULL on failure, in which case
is set appropriately.
The last six characters of template were not XXXXXX.
Now template is unchanged.
for other possible values for errno.
Available since glibc 2.1.91.
This function is present on the BSDs.