If any of the characters in illegal_characters or the NUL
character appears as an escaped character in escaped_string, then
that is an error and null will be returned. This is useful if you
want to avoid for instance having a slash being expanded in an
escaped path element, which might confuse pathname handling.
Unescapes a whole escaped string.
If any of the characters in illegal_characters or the NUL character appears as an escaped character in escaped_string, then that is an error and null will be returned. This is useful if you want to avoid for instance having a slash being expanded in an escaped path element, which might confuse pathname handling.