3.4.1 IMG_SetError

void IMG_SetError(const char *fmt, ...)

This is the same as SDL_SetError, which sets the error string which may be fetched with IMG_GetError (or SDL_GetError). This functions acts like printf, except that it is limited to SDL_ERRBUFIZE(1024) chars in length. It only accepts the following format types: %s, %d, %f, %p. No variations are supported, like %.2f would not work. For any more specifics read the SDL docs.

int myimagefunc(int i) { IMG_SetError("myimagefunc is not implemented! %d was passed in.",i); return(-1); }

See Also:
3.4.2 IMG_GetError