if [ condition ]; then if [ nested_condition ]; then nested if block fi fi Syntax:case $variable in pattern1)execute for pattern1 match ;;pattern2)execute for pattern2 match ;;)execute for no match esac 通过这些 if 语句，你可以根据特定条件在 Bash 脚本中实现复杂的逻辑操作。
Case 语句类似于 if 语句，但带有多个 elif。bash 脚本中的 Case 语句展开表达式，然后尝试找到与所有模...
Bash supports if-else statements so that you can use logical reasoning in your shell scripts. The generic if-else syntax is like this: if [ expression ]; then ## execute this block if condition is true else go to next elif [ expression ]; then ## execute this block if condition is ...
Checking the exit status using an ‘if’ statement in Bash Using a “if” statement and the “$?” variable, we can determine whether a command or script has executed successfully. Which holds the exit status of the most recent command executed, the syntax of the “if” statement for dete...
#!/bin/bashcase$1in"hello")echo"Hello, I am fine,thank you!";;"")echo"你必须要输入一个...
4. Bash If..then..else..if..then..fi..fi.. If [ conditional expression1 ] then statement1 statement2 . else if [ conditional expression2 ] then statement3 . fi fi If statement and else statement could be nested in bash. The keyword “fi” indicates the end of the inner if stateme...
The syntax of the "if" statement in Bash is as follows: if[condition]then# code to be executed if condition is trueelse# code to be executed if condition is falsefi Negating the "if" condition To negate the "if" condition, the logical operator!(NOT) is used. It reverses the logical...
Conditions in bash scripting (if statements) - Linux Academy Blog https://linuxacademy.com/blog/linux/conditions-in-bash-scripting-if-statements/ Table of conditions The following table list the condition possibilities for both the single- and the double-bracket syntax. Save a single exception, th...
Below is the general syntax ofIFELIFandELSEin bash: ifCONDITION-TO-TEST;then CODE-TO-EXECUTE-1 elifNEXT-CONDITION-TO-TEST;then CODE-TO-EXECUTE-2 elifNEXT-CONDITION-TO-TEST;then CODE-TO-EXECUTE-2 else CODE-TO-EXECUTE-2 fi Note: In the above general syntax that you can include zero, on...
在bash 脚本中,如果希望使用 if 语句应用多个条件,则使用 if elif else。在这种类型的条件语句中,如果满足第一个条件,则执行下面的代码,否则检查下一个 if 条件,如果不匹配,则执行下面的 else 语句中提到的命令。其语法和示例如下所示。 Syntax :