Shell 编程:流程控制
if 语句
if condition
thencommand1 command2...commandN
fi
if condition
thencommand1 command2...commandN
elsecommand
fi
if condition1
thencommand1
elif condition2
thencommand2
elsecommandN
fi
条件语句
- test 命令
[...]
等价于 test 命令
((...))
用于整数运算
[[...]]
Bash 提供的扩展关键字
for 循环
for var in item1 item2 ... itemN
docommand1command2...commandN
done
for 无限循环
for (( ; ; ))
while 循环
while condition
docommand
done
while 无限循环
while :
docommand
done
while true
docommand
done
until 循环
until condition
docommand
done
break 跳出循环
#!/bin/bash
while :
doecho -n "输入 1 到 5 之间的数字:"read aNumcase $aNum in1|2|3|4|5) echo "你输入的数字为 $aNum!";;*) echo "你输入的数字不是 1 到 5 之间的! 游戏结束"break;;esac
done
continue 跳过本次循环
#!/bin/bash
while :
doecho -n "输入 1 到 5 之间的数字: "read aNumcase $aNum in1|2|3|4|5) echo "你输入的数字为 $aNum!";;*) echo "你输入的数字不是 1 到 5 之间的!"continueecho "游戏结束";;esac
done