A string, may be null
Pointer to end of escaped_string, may be null
An optional string of illegal characters not to be allowed, may be null
an unescaped version of escaped_string, or null on error. The returned string should be freed when no longer needed. As a special case if null is given for escaped_string, this function will return null.
Unescapes a segment of an 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.
Note: NUL byte is not accepted in the output, in contrast to glib.uri.Uri.unescapeBytes.