linux中while循环
1、
[root@rhel7pc1 test]# ls test.sh [root@rhel7pc1 test]# cat test.sh #!/bin/bash NUM=10 while [ $NUM -gt 0 ] ## 循环条件 do echo "$NUM xxxx" let NUM-- ## 循环变量的变化 done [root@rhel7pc1 test]# bash test.sh 10 xxxx 9 xxxx 8 xxxx 7 xxxx 6 xxxx 5 xxxx 4 xxxx 3 xxxx 2 xxxx 1 xxxx
2、同上
[root@rhel7pc1 test]# ls test.sh [root@rhel7pc1 test]# cat test.sh #!/bin/bash NUM=10 while [ $NUM -gt 0 ] do echo "$NUM xxxx" let NUM-=2 done [root@rhel7pc1 test]# bash test.sh 10 xxxx 8 xxxx 6 xxxx 4 xxxx 2 xxxx
3、以交互方式决定循环次数
[root@rhel7pc1 test]# ls test.sh [root@rhel7pc1 test]# cat test.sh #!/bin/bash read -p "please input the loop times: " NUM while [ $NUM -gt 0 ] do echo "$NUM xxxx" let NUM-=1 done [root@rhel7pc1 test]# bash test.sh please input the loop times: 3 3 xxxx 2 xxxx 1 xxxx [root@rhel7pc1 test]# bash test.sh please input the loop times: 5 5 xxxx 4 xxxx 3 xxxx 2 xxxx 1 xxxx