PhysicsFS is a library to provide abstract access to various archives. See http://icculus.org/physfs/ for more information.

This addon makes it possible to read and write files (on disk or inside archives) using PhysicsFS, through Allegro’s file I/O API. For example, that means you can use the Image I/O addon to load images from .zip files.

You must set up PhysicsFS through its own API. When you want to open an ALLEGRO_FILE using PhysicsFS, first call al_set_physfs_file_interface, then al_fopen or another function that calls al_fopen.

These functions are declared in the following header file. Link with allegro_physfs.

     #include <allegro5/allegro_physfs.h>

# al_set_physfs_file_interface

    void al_set_physfs_file_interface(void)

Source Code

This function sets both the ALLEGRO_FILE_INTERFACE and ALLEGRO_FS_INTERFACE for the calling thread.

Subsequent calls to al_fopen on the calling thread will be handled by PHYSFS_open(). Operations on the files returned by al_fopen will then be performed through PhysicsFS. Calls to the Allegro filesystem functions, such as al_read_directory or al_create_fs_entry, on the calling thread will be diverted to PhysicsFS.

To remember and restore another file I/O backend, you can use al_store_state/al_restore_state.

> Note: due to an oversight, this function differs from al_set_new_file_interface and al_set_standard_file_interface which only alter the current ALLEGRO_FILE_INTERFACE.

> Note: PhysFS does not support the text-mode reading and writing, which means that Windows-style newlines will not be preserved.

See also: al_set_new_file_interface.

Examples:

- ex_physfs.c

# al_get_allegro_physfs_version

    uint32_t al_get_allegro_physfs_version(void)

Source Code

Returns the (compiled) version of the addon, in the same format as al_get_allegro_version.

Allegro version 5.2.11 - Last updated: 2026-02-09 02:00:43 UTC