#!/bin/sh # [1] If empty pin number #========================================================# if [ -z "$1" ]; then echo 127; exit 127; fi; # [2] Check if valid pin number (integer) #========================================================# test $1 -ge 0 2> /dev/null; if [ $? -gt 1 ]; then echo 127; exit 127; fi; # [3] Activate (if not already) #========================================================# test -d /sys/class/gpio/gpio$1 || echo $1 > /sys/class/gpio/export; # [4] Set mode to OUT #========================================================# echo "out" > /sys/class/gpio/gpio$1/direction; # [5] EXIT_CODE #========================================================# echo 0; exit 0;