Shell中判断语句if中-z至-d的意思 - sunny_2015 - 博客园 https://www.cnblogs.com/coffy/p/5748292.html 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 ...
It will after you learn about the if-else statements in bash shell scripting. 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 g...
While ‘else if’ is a powerful tool for handling multiple conditions in bash scripting, it’s not the only one. An alternative approach is the ‘case’ statement. ‘Case’ statements can be more readable and easier to maintain than a long list of ‘elif’ conditions, especially when you’...
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式的匹配。当找到匹配时,将执行所有语句,直到双分号 “;;”。如果没有找到匹配,则将执行 “*)” 模式下提到的语句。 Syntax : case expression in pattern1) statements ;; pattern2) statements ;; pattern3...
if-statement-bash-scripting-example Nested if Statement If 语句和 else 语句可以嵌套在 bash 脚本中...
Bash Shell Conditional Statements Conditionals let us decide whether to perform an action or not, this decision is taken by evaluating an expression. The most basic form is: if [ expression ]; then statements elif [ expression ]; then statements else statements fi ...
nesting if statements provide even greater flexibility and precision in your conditional logic. Mastering the Bash if statement is essential for effective scripting in Unix-based operating systems. By understanding its syntax, conditionals, and examples, you can create robust scripts that adapt to diffe...
以下是一些Bash 4+示例: 示例1,在字符串中检查是否存在'yes'(不区分大小写): if [[ "${str,,}" == *"yes"* ]] ;then 示例2,检查字符串中是否包含“yes”(不区分大小写): if [[ "$(echo "$str" | tr '[:upper:]' '[:lower:]')" == *"yes"* ]] ;then 示例三,检查字符串中是...
This lesson will cover bash scripting, in particular conditional statements using If commands. If statements are used to determine if certain actions are to be taken. Several examples of conditional statements will be provided and explained. Bash: If Bash scripts are used on the Linux operating ...
1. Bash If..then..fi statement if [ conditional expression ] then statement1 statement2 . fi This if statement is also called as simple if statement. If the given conditional expression is true, it enters and executes the statements enclosed between the keywords “then” and “fi”. If th...