is_windowed_mode(3) - Linux man page

Name

is_windowed_mode - Tells if you are running in windowed mode. Allegro game programming library.

Synopsis

#include <allegro.h>

int is_windowed_mode(void);

Description

This function can be used to detect wether or not set_gfx_mode() selected a windowed mode. Example: 
if (set_gfx_mode(GFX_AUTODETECT, 640, 480, 0, 0) != 0)
   abort_on_error("Couldn't set graphic mode!");
if (is_windowed_mode()) {
   /* Windowed mode stuff. */
} else {
   /* Fullscreen mode stuff. */
}

Return Value

Returns true if the current graphics mode is a windowed mode, or zero if it is a fullscreen mode. You should not call this function if you are not in graphics mode.

See Also

set_gfx_mode(3)