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 …….. ...
if [ condition_command ] then command1 command2 …….. last_command else ...
In this example, we will use if-else in shell script to make the interface for a password prompt. To do this, we will ask the user to enter the password and store it in the variable pass. If it matches the pre-defined password, which is ‘password’ in this example, the user will...
[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;
When I execute the shell script, and the operation enters in the if condition it never come back. It continuously executes the command "java -jar clientApplication.jar $s". But there is no problem in else condition. Is my syntax wrong or any logical error. ...
Let’s now try the same example without the proper spacing: $ if [ $(echo TEST)]; then echo CONDITION; fi bash: [: missing `]' $ if [$(echo TEST) ]; then echo CONDITION; fi bash: [TEST: command not found $ if [$(echo TEST)]; then echo CONDITION; fi bash: [TEST]: comma...
A: In shell scripts, “if-else” statements are used to regulate the flow of execution based on particular conditions. This structure lets you take different actions or run alternative code blocks depending on whether a condition is true or false. ...
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 ]...
an exit status of 1 indicates that the condition evaluated as false. In the first form of the utility shown using the SYNOPSIS: test [ condition ] the square brackets denote that condition is an optional operand and are not to be entered on the command line. ...
I've never done shell script before and now I'm running into a simple problem... I have a for loop which executes every time the run.sh script. To see how far the script has already run I want to print e.g. every 5000 the actual index. $counter = 0 for (( i = 0 ; i <...