1、判断语句
#!/bin/bash
if [ "$yn" == "Y" ] || [ "$yn" == "y" ]; then
echo "ok,continue!"
exit 0
fi
if [ "$yn" == "N" ] || [ "$yn" == "n" ]; then
echo "no,interrupt!"
exit 0
fi
echo "sorry,i dont know what is your choice" && exit 0
2、case ...esac
举例子:
#!/bin/bash
case $1 in
"hello")
echo "hello,how are you!"
;;
"")
echo "you must input someword"
;;
*)
echo "Usage $0 {hello}"
;;
esac
3、function fname() {
程序段
}
4、循环
while [ condition ]
do
程序段落
done
例子
while [ "$yn" != "YES" ] && [ "$yn" != 'yes' ]
do
read -p "please input yes/YES to stop the program" yn
done
同理
until [ condition ]
do
程序段落
done
5、已经知道要循环几次
for (( 初始值; 限制值; 执行步长 ))
do
程序段
done
6、脚本的追踪与调试
sh [-nvx] scripts.sh
参数-n: 不执行脚本,仅查询语法
-v:执行脚本前,将脚本输出到屏幕上
-x:将使用的脚本显示到屏幕上