Conditions in bash scripting (if statements) - Linux Academy Blog https://linuxacademy.com/blog/linux/conditions-in-bash-scripting-if-statements/ Table of conditions The following table list the condition possibilities for both the single- and the double-bracket syntax. Save a single exception, th...
1、if语法格式 1.1 if格式 if condition; then commands; fi 1.2 else if 和 else if c...
[shell script] if condition and Usage 我们先来看一段shell脚本, [ $# -lt2] &&{echo"Usage: $0 target store_dir">&2exit2} 这段代码真的很精简,专业而成熟; 其中包含的知识点有if条件,&&技巧,{}的块语块作用,重定向;
if [ condition_command ] then command1 command2 …….. last_command elif [ ...
For Mathematics, use following operator in Shell Script Mathematical Operator in Shell Script Meaning Normal Arithmetical/ Mathematical Statements But in Shell For test statement with if command For [ expr ] statement with if command -eq is equal to 5 == 6 if test 5 -eq 6 if [ 5 -eq 6...
PowerShell 複製 $condition = $true if ( $condition ) { Write-Output "The condition was true" } 語句做的第一件事 if 是在括弧中評估表達式。 如果評估為 $true,則會在大括弧中執行 scriptblock。 如果值為 $false,則會略過該腳本區塊。
In this example, the script fails because there are no spaces between the brackets and the variables. The correct syntax isif [ $a -gt $b ]; then. Error: Incorrect Condition Another common error is using the wrong operator in the condition. For example, using ‘=’ instead of ‘-eq’...
在Shell脚本中,if语句的基本语法如下: ``` if [ condition ] then commands fi ``` 其中,condition是一个判断条件,如果条件成立(返回真),则执行commands中的命令。在if语句中,常用的条件判断符号包括: - -eq: 等于 - -ne: 不等于 - -lt: 小于 ...
PowerShell $condition=$trueif($condition) {Write-Output"The condition was true"} if语句执行的第一步是计算括号中的表达式。 如果计算结果为$true,则执行大括号中的scriptblock。 如果值为$false,则会跳过该脚本块。 在上面的示例中,if语句仅计算$condition变量。 其计算结果为$true,将在脚本块内执行Wri...
shell脚本(8)-流程控制if 一、单if语法 1、语法格式: if[ condition ] #condition值为 then commands fi 1. 2. 3. 4. 2、举例: [root@localhost test20210725]# vim document.sh #!/usr/bin/bash #假如没有/tmp/abc这个文件夹,就创建一个if[ ! -d /tmp/abc ]...