SYNOPSIS

#include "SDL.h"

SDLMod SDL_GetModState(void);

DESCRIPTION

Returns the current state of the modifier keys (CTRL, ALT, etc.).

RETURN VALUE

The return value can be an OR'd combination of the SDLMod enum.

SDLMod

typedef enum {
  KMOD_NONE  = 0x0000,
  KMOD_LSHIFT= 0x0001,
  KMOD_RSHIFT= 0x0002,
  KMOD_LCTRL = 0x0040,
  KMOD_RCTRL = 0x0080,
  KMOD_LALT  = 0x0100,
  KMOD_RALT  = 0x0200,
  KMOD_LMETA = 0x0400,
  KMOD_RMETA = 0x0800,
  KMOD_NUM   = 0x1000,
  KMOD_CAPS  = 0x2000,
  KMOD_MODE  = 0x4000,
} SDLMod;

 SDL also defines the following symbols for convenience: 

#define KMOD_CTRL (KMOD_LCTRL|KMOD_RCTRL)
#define KMOD_SHIFT  (KMOD_LSHIFT|KMOD_RSHIFT)
#define KMOD_ALT  (KMOD_LALT|KMOD_RALT)
#define KMOD_META (KMOD_LMETA|KMOD_RMETA)