Simple blink shell script

blink.sh

#!/bin/sh

if [ ! -e '/sys/class/gpio/gpio7' ]; then
  echo "GPIO 7 is not exported, setting it up..."
  echo 7 > /sys/class/gpio/export
  echo out > /sys/class/gpio/gpio7/direction
fi

echo "Ctrl+C to quit, blinking now"
while [ 1 ]; do
  sleep 1
  echo 0 > /sys/class/gpio/gpio7/value
  sleep 1
  echo 1 > /sys/class/gpio/gpio7/value
done