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 …….. last_command else command1 command2 …….. ...
When trying to understand the working of a function like if-else in a shell script, it is good to start things simple. Here, we initialize two variables a and b, then use the if-else function to check if the two variables are equal. The bash script should look as follows for this t...
1、if语法格式 1.1 if格式 if condition; then commands; fi 1.2 else if 和 else if c...
以下是关于Shell脚本中if语句的基础概念、优势、类型、应用场景以及常见问题的解答。 基础概念 if语句的基本结构如下: 代码语言:txt 复制 if condition then # 执行的命令或代码块 elif another_condition then # 另一个条件满足时执行的命令或代码块 else # 所有条件都不满足时执行的命令或代码块 fi 优势 自动化...
Here, based on the result ofTEST_COMMAND, the script either executes theTHEN_EXPRESSIONSorELSE_EXPRESSIONS. Obviously, there’s a lot of spacing in the above scripts, much of which may not be needed. Let’s see how we can use that to our advantage. ...
else if condition;then action; else action; fi 注意:if和slse语句可以进行嵌套,if条件判断可能因此变得很长,可以使用逻辑运算符使他变得简洁一点: [ condition ] && action; #如果condition条件为真,则执行action; [ condition ] || action; #如果condition条件为假,则执行action; ...
In this example, the script first checks if ‘a’ is greater than ‘b’. If it’s not, it moves on to the ‘elif’ statement to check if ‘a’ is greater than ‘c’. If neither condition is met, it executes the ‘else’ statement, which in this case, prints ‘a is not greate...
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 ]...
zutuanxue.com #Created Time: #Script Description: if [ $USER == 'root' ] then echo "hey admin" else echo "hey guest" fi 四、if…elif…else 适用范围:多于两个以上的判断结果,也就是多于一个以上的判断条件。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 if [ condition 1] 满足第一...
如果if语句后放入一个不能工作的命令,则状态码为非0,且bash shell会跳过then后面的语句。 [22:43:53 root@libin3 libin]# vim shell21 /bin/bash #this is result error if libin then echo "this is error" fi if date then echo "this is success" ...