while do done, until do done (不定回圈)
当 condition 条件成立时,就进行回圈,直到 condition 的条件不成立才停止
while [condition] -->中括号内的状态就是判断式
do -->回圈的开始
程序段落
done -->回圈的结束
例如: #!/bin/bash num=1 while [ $num -le 10 ] do echo -e " the num is $num" let num=num+1 done 运行输出: the num is 1 the num is 2 the num is 3 the num is 4 the num is 5 the num is 6 the num is 7 the num is 8 the num is 9 the num is 10