debian man page for pack_fopen_vtable

pack_fopen_vtable(3alleg4)					  Allegro manual					pack_fopen_vtable(3alleg4)

NAME
       pack_fopen_vtable - Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       PACKFILE *pack_fopen_vtable(const PACKFILE_VTABLE *vtable, void *userdata);

DESCRIPTION
       Creates	a  new	packfile  structure that uses the functions specified in the vtable instead of the standard functions. The data pointer by
       `vtable' and `userdata' must remain available for the lifetime of the created packfile.

       While the created packfile structure can be used with other Allegro functions, there are  two  limitations.  First,  opening  chunks  using
       pack_fopen_chunk()  on top of the returned packfile is not possible at this time. And packfile_password() does not have any effect on pack-
       files opened with pack_fopen_vtable().

RETURN VALUE
       On success, it returns a pointer to a PACKFILE structure, and on error it returns NULL and stores an error code in `errno'.

SEE ALSO
       pack_fopen(3alleg4), pack_fopen_chunk(3alleg4), packfile_password(3alleg4), expackf(3alleg4)

Allegro 							   version 4.4.2					pack_fopen_vtable(3alleg4)