首页Linux if语句常用shell脚本

Linux if语句常用shell脚本

时间: 2023-10-21 18:19:23 浏览: 89

1. 判断文件是否存在 ```bash if [ -f /path/to/file ]; then echo "File exists" else echo "File does not exist" fi ``` 2. 判断目录是否存在 ```bash if [ -d /path/to/dir ]; then echo "Directory exists" else echo "Directory does not exist" fi ``` 3. 判断字符串是否为空 ```bash if [ -z "$string" ]; then echo "String is empty" else echo "String is not empty" fi ``` 4. 判断两个字符串是否相等 ```bash if [ "$str1" = "$str2" ]; then echo "Strings are equal" else echo "Strings are not equal" fi ``` 5. 判断数字大小 ```bash if [ $num1 -gt $num2 ]; then echo "$num1 is greater than $num2" else echo "$num1 is less than or equal to $num2" fi ``` 6. 判断命令执行结果 ```bash if command; then echo "Command succeeded" else echo "Command failed" fi ``` 7. 嵌套if语句 ```bash if [ condition1 ]; then if [ condition2 ]; then #statements fi fi ``` 8. 判断脚本参数个数 ```bash if [ $# -eq 0 ]; then echo "No arguments provided" else echo "Number of arguments: $#" fi ``` 9. 判断用户是否有执行脚本的权限 ```bash if [ "$(whoami)" != "root" ]; then echo "You do not have permission to run this script" exit 1 fi ``` 10. 判断系统类型 ```bash if [ "$(uname)" == "Linux" ]; then echo "This is a Linux system" elif [ "$(uname)" == "Darwin" ]; then echo "This is a macOS system" else echo "Unknown system type" fi ```

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