osx man page for install_keyboard

install_keyboard(3alleg4)					  Allegro manual					 install_keyboard(3alleg4)

NAME
       install_keyboard - Installs the Allegro keyboard interrupt handler.

SYNOPSIS
       #include <allegro.h>

       int install_keyboard();

DESCRIPTION
       Installs  the  Allegro keyboard interrupt handler. You must call this before using any of the keyboard input routines. Once you have set up
       the Allegro handler, you can no longer use operating system calls or C library functions to access the keyboard.

       Note that on some platforms the keyboard won't work unless you have set a graphics mode, even if this  function	returns  a  success  value
       before  calling set_gfx_mode. This can happen in environments with graphic windowed modes, since Allegro usually reads the keyboard through
       the graphical window (which appears after the set_gfx_mode call). Example:

	  allegro_init();
	  install_timer();
	  install_keyboard();
	  /* We are not 100% sure we can read the keyboard yet! */
	  if (set_gfx_mode(GFX_AUTODETECT, 640, 480, 0, 0) != 0)
	     abort_on_error("Couldn't set graphic mode!");

	  /* Now we are guaranteed to be able to read the keyboard. */
	  readkey();

RETURN VALUE
       Returns zero on success, or a negative number on failure (but you may decide not to check  the  return  value  as  this	function  is  very
       unlikely to fail).

SEE ALSO
       remove_keyboard(3alleg4),  poll_keyboard(3alleg4),  key(3alleg4),  keypressed(3alleg4), readkey(3alleg4), ureadkey(3alleg4), keyboard_call-
       back(3alleg4),	keyboard_ucallback(3alleg4),   keyboard_lowlevel_callback(3alleg4),   three_finger_flag(3alleg4),   key_led_flag(3alleg4),
       set_leds(3alleg4), set_keyboard_rate(3alleg4), set_gfx_mode(3alleg4)

Allegro 							   version 4.4.2					 install_keyboard(3alleg4)