man make_relative_filename () - Tries to make a relative filename from absolute path and filename. Allegro game programming library.
NAME
make_relative_filename - Tries to make a relative filename from absolute path and filename. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
char *make_relative_filename(char *dest, const char *path, const char *filename, int size);
DESCRIPTION
Attempts to make a relative filename from an absolute path and an absolute filename, storing at most `size' bytes into the `dest' buffer. This function won't work if the paths are not canonical under the current platform (see canonicalize_filename()). Also, `dest' cannot be used as input value for `path' or `filename'. Example:
char base[] = "/long/absolute/path/program.exe";
char user_input[] = "/nice/and/short.txt";
...
make_relative_filename(buf, base, user_input, sizeof(buf));
/* Under Unix buf would contain:
../../../nice/and/short.txt */
RETURN VALUE
Returns a copy of the `dest' parameter if it succeeds or NULL if it fails (eg. under DOS, one path starts with "C:\" and another with "A:\").