Linux shell学习（六）while循环 until循环

下面是例子程序：

#!/bin/bashecho "==========while=========="var=10while [ $var -gt 0 ]do        echo $var        var=$[ $var - 1 ]doneecho "==========until=========="bb=18until [ $bb -eq 0 ]do        echo $bb        bb=$[ $bb -3 ]doneIFS.OLD=$IFSIFS=$'\n'for entry in `cat 123.txt`do        echo $entry        IFS=:        for x in $entry        do                echo "the x is $x"        donedone#done > 222.txt

下面是运行截图：