Shell 支持任意数目的分支，当分支比较多时，可以使用 if elif else 结构，它的格式为：ifcondition1the...
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 ] then mkdir-pv /tmp/abc echo "...
1.1 if格式 if condition; then commands; fi 1.2 else if 和 else if condition; then...
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 …….. ...
Table of conditions The following table list the condition possibilities for both the single- and the double-bracket syntax. Save a single exception, the examples are given in single-bracket syntax, but are always compatible with double brackets. ...
[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;
Using else if statement in bash You can use an elif (else-if) statement whenever you want to test more than one expression (condition) at the same time. For example, the followingage.shbash script takes your age as an argument and will output a meaningful message that corresponds to your...
In fact, [ is essentially the test command. Thus, similar to other commands, whitespace is required after opening and before closing brackets: $ if [ $(echo TEST) ]; then echo CONDITION; fi CONDITIONCopy Let’s now try the same example without the proper spacing: $ if [ $(echo TEST)...
shell if fi的意思shell if fi的意思 shell脚本中的if-fi结构是条件语句,用于根据条件来执行不同的代码块。if-fi结构的意思是,如果满足某个条件,则执行某些特定的操作,否则执行其他操作。在shell脚本中,if-fi结构通常如下所示: shell. if [ condition ] then. # 在这里执行条件成立时的操作。 else. # 在...
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...