/* Toggle keyboard light on Fujitsu U810.  Install as suid root.  */

#include <stdio.h>

#define KBD_LIGHT "/sys/class/leds/kbd_light/brightness"

int main (void)
{
  FILE *fh;
  int val;

  fh = fopen (KBD_LIGHT, "r");
  if (!fh)
    return 1;
  if (fscanf (fh, "%i", &val) != 1)
    return 1;
  fclose (fh);

  fh = fopen (KBD_LIGHT, "w");
  if (!fh)
    return 1;
  fprintf (fh, "%i", 255 - val);
  fclose (fh);

  return 0;
}