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 …….. ...
在 Shell 脚本中，if 语句后面加不加分号都是可以的。分号在 Shell 中是一种命令分隔符，它用于分隔...
if[command];thenelsefi 1.3 if语法格式 代码语言:shell AI代码解释 if[command];thenfi 2. 字符串运算符 代码语言:text AI代码解释 = 检测两个字符串是否相等,相等返回 true。 [ $a = $b ] 返回 false。 != 检测两个字符串是否不相等,不相等返回 true。 [ $a != $b ] 返回 true。 -z 检测字符...
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...
Similarly, shell functions can return an exit status by including an integer argument to thereturn command. If we were to convert the script above to a shell function to includeit in a larger program, we could replace the exit commands with return statementsand get the desired behavior: 类似...
[22:55:06 root@libin3 libin]# vim shell22 #!/bin/bash # the multiple command in the then-if rhce=student # if grep $rhce /etc/passwd;then echo "this is rhcsa" echo "this is rhce" echo "this is put in command echo:"
Shell script之if...then 1 Variable in shell If you want to print variable, then useechocommand. In front of the variable to add$variabelor use${variable}to fetch the value of variable. #echo$variable #echo$PATH 2 if...then ifconditionthencondition is true ...
1)command ‘script’ filenames command是awk或sed,script是可以被awk或sed理解的命令清单,filenames表示命令所作用的文件清单。 2)正规表达式基本构造块包括: 普通字符:大小写字母、数字、字符。 元字符:.、*、[chars]、^、$、/。例:/a.c/匹配如a+c, a-c, abc行。
Shell if 条件判断 2019-12-20 09:41 −Shell 语言中的if条件 一、if的基本语法: ``` if [ command ];then 符合该条件执行的语句 elif [ command ];then 符合该条件执行的语句 else 符合该条件执行的语句 fi ``` 二、文件/文件夹(目录)判断 ``` [ -b FILE ] ... ...
If you want to run a shell script in the background, but you do not know how to do that, read this article. Here you will find out how to put a command in the background.