Bash Shell中主要提供了三种循环方式:for、while和until。 一、for循环 for循环的运作方式,是讲串行的元素意义取出,依序放入指定的变量中,然后重复执行含括的命令区域(在do和done 之间),直到所有元素取尽为止。 其中,串行是一些字符串的组合,彼此用$IFS所定义的分隔符(如空格符)隔开,这些字符串称为字段。 for的...
您可以使用@来计算算术表达式，例如@ x = 2 + 2将$x设置为4;把它作为练习。将算术表达式括在反引...
/bin/bashwhile! bash -n$1&>/dev/null ;doread-p"Scripts syntax error,Please input any key edit scripts or q|Q quit: "SCRIPTcase$SCRIPTinq|Q)echo"quit edit..."exit8 ;; *) vim$1;;esacdone检查脚本,脚本语法错误时将进入循环;当输入q或者Q时,退出脚本;当输入任意键则vim编辑脚本,脚本修改...
PowerShell复制 while($val-ne3) {$val++Write-Host$val} 在此示例中,条件 ($val不等于 3) 为 true,而$val等于 0、1 和 2。 每次通过 循环时,$val使用++一元递增运算符递增 1。 最后一次循环$val设置为 3,条件语句的计算结果为 false,循环退出。
hdc shell命令是否支持schema uri模拟跳转 是否可以通过ApplicationContext启动UIAbility 使用hdc命令安装release HAP包到设备时上报“INSTALL_FAILED_APP_SOURCE_NOT_TRUSTED”错误 如何查询应用包的名称、供应商、版本号、版本文本、安装时间、更新时间描述信息 如何安装打包出来的App包(通过什么命令安装) 如何判断应...
Bash while Loop Syntax The syntax of Bash while loop is as follows: while [condition] do commands_to_execute done The while loop is initiated with thewhile, succeeded by the condition enclosed withinthedoanddonekeywords. The script to printWelcome to Bash Scripting5 times using the while loop...
The syntax of the while loop Multiple examples of the while loop So let's start with the first one. How to use the while loop in bash Like any other loop, while loop does have a condition statement and the condition is the crucial factor to iterate the loop. ...
Let’s break downwhile loopsyntax. while loopshould start with a while keyword followed by a condition. Aconditionshould be enclosed within[ ]or[[ ]]. The condition should always return true for the loop to be executed. The actual block of code will be placed betweendoanddone. ...
To ensure that the loop terminates naturally, you should add one or more break statements wrapped in proper conditions: Python Syntax while True: if condition_1: break ... if condition_2: break ... if condition_n: break This syntax works well when you have multiple reasons to end the...
The syntax of thewhilecommand is: while 命令的语法是: while commands; do commands; done 1. Likeif,whileevaluates the exit status of a list of commands. As long as the exit statusis zero, it performs the commands inside the loop. In the script above, the variablecountis created and assig...