The string comparison can be a little tricky using the while loop. In the context of shell scripting the-eqare calledinteger comparison operators. So, these operators cannot be used to compare strings. To compare strings in the shell scripting the string comparison operators=,==,!=are used. ...
Example 1: Infinite While loop in a shell script An infinite While loop means your script will run the loop commands non-stop. Infinite While loops never stop running and this occurs when the condition always turns out to be “True.” ...
statements2if(disaster-condition)thenbreak #Abandon the loop.fistatements3 #While good and, no disaster-condition.done Following shell script will go though all files stored in /etc directory. The for loop will be abandon when /etc/resolv.conf file found. #!/bin/bashforfilein/etc/*do if ...
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...
For example, you can run UNIX command or task 5 times or read and process list of files using a for loop. A for loop can be used at a shell prompt or within a shell script itself. for loop syntax Numeric ranges for syntax is as follows: ...
Bash While 循环 Shell 编程语言提供的另一个迭代语句是 while 语句。 Syntax:whileexpressiondocommands done 在上面的while循环语法中: while、do、done 是关键字 表达式是返回标量值的任何表达式 While 语句导致在提供的条件表达式为真时执行代码块。 Bash While 示例 3. 将内容写入文件 ...
The bash loop constructs include the for loop, while loop, and until loop. 👉 Sometimes, you may find references to a select loop in bash. It is not part of the bash loop constructs. You can read more about the select-loop in my post How To Create Simple Menu with the Shell ...
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: #!/bin/bash counter=$1 factorial=1 while [ $counter -gt 0 ] ...
One can use the for loop statement even within a shell script. While the For Loop is a prime statement in many programming languages, we will focus on how to use it for the bash language. Are you ready to add yet another tool to your developer arsenal? Let’s explore deeper into the...
——Bash For、While、Until循环示例 循环语句用于强制程序重复执行语句,执行的语句称为循环体。 循环一直执行,直到控制表达式的值为 0。控制表达式可以是任何标量数据类型。 shell 语言还提供了几个迭代或循环语句。在本文中,让我们通过一些示例来了解 bash 提供的循环语句。