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. ...
In Linux,whileloopsare essential tools for automating repetitive tasks and controlling the flow of programs.These loops enable us to execute a block of code repeatedly, provided that a specified condition is true. Moreover,whileloops are versatile in that we can include user input as the specifie...
Androidshell脚本while循环shell脚本中的while循环 最后要介绍的是shellscript 设计中常见的"循环"(loop)。所谓的loop 就是 script中的一段在一定条件下反复执行的代码。 bashshell中常用的loop 有如下三种: * for *while* until for loop 是从一个清单列表中读进变量值,并"依次"的循环执行 do 到 done 之间的...
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...
Shell编程中循环命令用于特定条件下决定某些语句重复执行的控制方式,有三种常用的循环语句:for、while和until。while循环和for循环属于“当型循环”,而until属于“直到型循环”。循环控制符:break和continue控制流程转向。 参考:《Linux 与unix shell 编程指南》 ...
如何在Linux中从shell脚本调用另一个shell脚本 通常在Linux上,您可以使用crontab来执行此类调度任务。但是,您必须指定“设置计时器”的时间,因此,如果您希望在文件本身中配置计时器,则必须为此创建一些机制。 例如,您可以添加crontab 30 1 * * 5 /path/to/script/script.sh 将在每周五凌晨1:30执行脚本: 30分钟 ...
breakexits from afor,select,while, oruntilloop in a shell script. Ifnumberis given,breakexits from the given number of enclosing loops. The default value ofnumberis1. Usage Notes This is a special built-in command of the shell. Exit Values ...
To compare strings in the shell scripting the string comparison operators=,==,!=are used. Let’s create a Bash script to take the username as input from the user and compare the name string with the hardcoded name. #!/bin/bash
在停止while循环在输出中重复的问题上,可以采取以下几种方法: 1. 使用break语句:在while循环内部设置一个条件,当满足该条件时,使用break语句跳出循环。这样可以确保循环在满足条件后...
One-line While loop example: The code above will instruct your system to run command1, command2, command3, and command4 continually until the condition turns to “True.” Example 1: Infinite While loop in a shell script An infinite While loop means your script will run the loop commands ...