debian man page for is_relative_filename

is_relative_filename(3alleg4)					  Allegro manual				     is_relative_filename(3alleg4)

NAME
       is_relative_filename - Returns TRUE if the filename is relative. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       int is_relative_filename(const char *filename);

DESCRIPTION
       Returns	TRUE  if  the  filename is relative or FALSE if it is absolute. Note that an absolute filename under DOS (with a device separator)
       will be considered as relative under Unix, because there absolute paths always start with a slash.

SEE ALSO
       make_absolute_filename(3alleg4), make_relative_filename(3alleg4)

Allegro 							   version 4.4.2				     is_relative_filename(3alleg4)