[shell]简单的shell提示和参数脚本

该shell脚本有如下点：

• bash or dash
• case语句的写法
• 脚本help写法
• 参数是否为空的写法
• 参数

#! /bin/bash
case "$1" in
    -h|--help|?)
    echo "Usage: 1st arg:pin name, 2st arg:reset time"
    echo "1st arg pin name:lte-reset,zigbee-reset"
    echo "2st arg reset time in ms"
    exit 0
;;
esac

if [ ! -n "$1" ]; then
    echo "pls input 1st arg"
    exit
fi

if [ ! -n "$2" ]; then
    echo "pls input 2st arg"
    exit
fi

echo "you will reset $1 with $2ms"
echo 0 > /home/gpio/$1
time=$[ $2 * 1000 ]
echo $time > /home/gpio/$1