As long as thewhileloop condition remains true, the code block within the loop is executed repeatedly.In contrast, the loop terminates if the condition evaluates to false. 3. Including User Input Into awhileLoop Condition In shell scripting, using user input as a condition for awhileloop adds...
shell脚本elsesshell脚本while while循环循环语句常用于重复执行一条指令或一组指令,直到条件不满足停止,shell脚本语言的循环语句常见的有while、until、for、select循环语句,其中,until和select已经基本淡出历史舞台。本章讲while循环while循环语句主要用来重复执行一组命令会语句。在企业中常用于守护进程或持续运行的程序,也...
One of the many scripting constructs is the loop. A loop is a section of code that picks up data or generates data and then performs some operation on the data and then begins the process over again until some condition is met, the script is disrupted, or when input data is exhausted. ...
while[condition]dostatements1#Executedaslongascondition istrueand/or, up to a disaster-conditionifany.statements2if(disaster-condition)thenbreak#Abandon thewhilelopp.fistatements3#While good and, no disaster-condition.done In this example, the break statement will skip the while loop when user ente...
condition为true时命令1到命令3将会一直执行,知道条件为false ,例如: 1. #!/bin/bash x=1 while [ $x -le 5 ] do echo "Welcome $x times" x=$(( $x + 1 )) done 1. 2. 3. 4. 5. 6. 7. Here is a sample shell code to calculate factorial using while loop: ...
script标签可以放在页面的任何位置,一般在head和body中。当引入文件和内部js同时存在时,内部js不会执行。 不能使用的单标签。 js 语句严格区分大小写。...Math.round()四舍五入(针对整数) 4.逻辑控制与流程控制 (a) if语句: if (bool表达式){ 语句 } else if (bool表达式){ 语句 }...语句: while(...
LEAVE read_loop; END IF;--结束标记,在循环体中判断并跳出。 END LOOP;--关闭游标 CLOSE cs1;--游标2 OPEN cs2; SET done=0;--REPEAT循环 REPEAT--FETCH 游标中的列必须要和INTO的列数量和类型一致。--如果游标中没有新的可用行,即Fetch到空行,则会触发NOT FOUND异常,就会把done设置为1。
Let’s create a Bash while loop that will display numbers 1 to 5 and skip number 2. #!/bin/bash i=0 while [ $i -lt 5 ] do i=$(( $i+1 )) if [ $i -eq 2 ] then continue fi echo $i done In the above script, anifcondition is specified to tell the program tocontinueand...
Describe the bug I am using QEMU to run shell_uart. In shell "execute" function, there is a while loop to parse each argument from "sh->ctx->cmd_buff" one at a time. One of the AND condition is "args_left > 0" which means there is argument needs to be parsed. ...
读出的shell内置命令告诉while循环逐行读取myhosts线和分配每行变量的主机,然后传递给ping命令的内容。 #! /bin/bash # This script is used to demonstrate the use of awhileloopwhileread host; do ping -c 2 # fsck -n /dev/sdg1 根据fsck输出中的错误消息,我们将知道我们是否可以尝试自己解决问题或将其...