If-statement-Bash-Script-Example if-else Statement 除了普通的 if 语句之外，我们还可以用 else 块扩展 if 语句。基本思想是，如果语句为真，则执行 if 块。如果语句为假，则执行 else 块。Syntax :if [ condition_command ] then command1 command2
如果 condition1 成立，那么就执行 if 后边的 statement1；如果 condition1 不成立，那么继续执行 elif，...
If theconditionevaluates to TRUE, the processor will execute the statement(s) followed by the keywordthen. In the syntax, it is mentioned asstatement1. In a case where theconditionevaluates to FALSE, the processor will execute the statement(s) followed by the keywordelse. This is denoted ass...
'Else if'in bash scripting, often written as'elif', is used to check multiple conditions in your code. It is used with the syntax,if [firstStatement]; then... elif [secondCondition]; then... else. It’s a powerful tool that allows your scripts to make decisions based on various scen...
The words if, then, else, and fi in the preceding script are shell keywords; everything else is a command. This distinction is extremely important because one of the commands is $ 1 = "hi" and the [ character is an actual program on a Unix system, not special shell syntax. (This is...
善用这个观念,对精简 script 有相当的帮助。 ! 惊叹号(negate or reverse) 通常它代表反逻辑的作用,譬如条件侦测中,用 != 来代表"不等于" 1 2 3 4 5 6 7 8 9 [root@VM_16_9_centos ~]# cat a.sh #!/bin/bash if["$?"!= 0 ];then ...
Syntax <condition> ? <if-true> : <if-false> 三元运算符的行为类似于简化if-else语句。 计算<condition>表达式,并将结果转换为布尔值,以确定接下来应计算哪个分支: 如果<condition>表达式为 true,则执行<if-true>表达式 如果<condition>表达式为 false,则执行<if-false>表达式 ...
善用这个观念,对精简 script 有相当的帮助。 ! 惊叹号(negate or reverse) 通常它代表反逻辑的作用,譬如条件侦测中,用 != 来代表"不等于" [root@VM_16_9_centos ~]# cat a.sh #!/bin/bash if [ "$?" != 0 ];then echo "Executes error" ...
exit $count # terminate the script with some accumulated count 8.6 switch 语句 语法: Syntax 复制 switch-statement: switch new-lines~opt~ switch-parameters~opt~ switch-condition switch-body switch-parameters: switch-parameter switch-parameters switch-parameter switch-parameter: -regex -wildcard -ex...
SYNTAX New-Module [-Name] <System.String> [-ScriptBlock] <System.Management.Automation.ScriptBlock> [-ArgumentList <System.Object[]>] [-AsCustomObject] [-Cmdlet <System.String[]>] [-Function <System.String[]>] [-ReturnResult] [<CommonParameters>] DESCRIPTION The `New-Module` cmdlet ...