f FILE—— 如果 ref="https://linuxize.com/post/bash-check-if-file-exists/">FILE 存在,并且是常规文件(不是目录或设备什么的) ,则为真。 结论 if、if..else 和if..elif..else 语句让我们能够基于不同的判断条件来控制 Bash 脚本中逻辑语句的执行。 如果你有任何疑问或反馈,请随时发表评论。
The Bash if statement is a fundamental construct that allows you to control the flow of your scripts based on specific conditions. By leveraging conditionals, such as numeric and string comparisons, and file and directory checks, you can create dynamic and responsive scripts. Additionally, nesting ...
Why you should not use the || and && operators instead of a Bash If Statement? Detailed Examples & FAQ How to check if a variable exists or is “null”? How to check if a file exists? How to check if a directory exists? How to check if a command succeeds or failed? How to do...
因为在此场景下数字1,2,3都是按字符串"1","2","3"类进行比较的,也就是说调用者传入的都是字符串。 附件: bash的if语句语法 if [ conditional-expression1 ]; then statement... elif [ conditional-expression2 ]; then statement... else statement... fi 注意关键字then可以换行起,但我个人还是喜欢...
Statement1 elif Expression2; then Statement2 else Statement3 fi 基础语法说明: if语句必须以单词fi终止。elif和else为可选项,表示其他条件 使用示例: 判断文件是否存在 #! /bin/bash if [ -f 123.txt ];then echo "file exists" else echo "file not exists" ...
File exists Explanation: In the exercise above, The variable 'file_to_check' holds the name of the file we want to check. The "if" statement checks if the file exists using the -e test operator. If the file exists, it prints "File exists" and exits with code 0, indicating success....
9. Bash if / else / fi statements 9.1. Simple Bash if/else statement Please note the spacing inside the [ and ] brackets! Without the spaces, it won't work! #!/bin/bash directory="./BashScripting" # bash check if directory exists ...
File/usr/bin/boot.ini exists 请参阅之前的文章以了解各种bash if 语句类型。 Bash 示例 2. 比较数字 下面的脚本从用户那里读取两个整数,并检查这两个数字是否相等或大于或小于彼此。 $ cat numbers.sh #!/bin/bash echo"Please enter first number"read first ...
and elif. Then we'll look at a few of the "primary" operators you can leverage in a conditional statement such as = for string equality, -eq for numeric equality, and -e to check if a file exists. After that, we'll use conditional statements to create a function that asserts that ...
然后构造一个 ls 命令来判断,不需要反单引号包围,套到 if 语句里: $ if ls exists.txt; then echo yes; else echo no; fi exists.txt yes $ if ls not_exists.txt; then echo yes; else echo no; fi ls: cannot access not_exists.txt: No such file or directory no ...