shell until 循环

until 循环

格式：

until condition
do
    command
done

#输出0～9

#!/bin/bash
a=0
until [ ! $a -lt 10 ]
do
   echo $a
   a=`expr $a + 1`
done

结果输出：

0
1
2
3
4
5
6
7
8
9