How to check if a command succeeds or failed? How to do string comparison and check if a string equals to a value? How to check if a string is in an array? How to use the Bash ternary operator? How to negate an if condition in a Bash if statement? (if not command or if not ...
'Else if'in bash scripting, often written as'elif', is used to check multiple conditions in your code. It is used with the syntax,if [firstStatement]; then... elif [secondCondition]; then... else. It’s a powerful tool that allows your scripts to make decisions based on various scen...
For this, we need to utilize the not operator “!” with the “if” statement in the bash script. Let’s discuss the use of the “if-not” operator in Bash programming with the help of some examples. Get started with the new Bash file creation while using the terminal shell of the ...
Example 1: If statement in bash on string equality #!/bin/bash read-p"Enter a match word: "USER_INPUT if[[$USER_INPUT=="hello"]];then echo"Hello to you as well" fi In this example above we use the basicIFcondition with a single test of string equality and then print some output...
-ge 大于等于,如:if [ "a"−ge"b" ] -lt 小于,如:if [ "a"−lt"b" ] -le 小于等于,如:if [ "a"−le"b" ] < 小于(需要双括号),如:(("a"<"b")) <= 小于等于(需要双括号),如:(("a"<="b")) > 大于(需要双括号),如:(("a">"b")) ...
if..then..else..if..then..fi..fi..(Nested Conditionals) 语法: if [[ condition ]] then statement elif [[ condition ]]; then statement else do this by default fi 1. 2. 3. 4. 5. 6. 7. 8. 为了创建有意义的比较,我们也可以使用AND -a和OR -o。
if [ $x = "name" ] then echo "hello" fi 运行脚本时出现此错误 -example.sh: line 2: [: =: unary operator expected 但是,如果使用if [ "$x" = "name" ]它将正常运行(即没有错误),并且ifstatement被评估为false,则x值为null,与name不匹配。
if Statement if...else Statement if...elif...else Statement Nested if Statements Multiple Conditions Test Operators Conclusion Share: This article will walk you through the basics of the bash if...else statement and explain you how to use it in your shell scripts. Decision-making is one ...
It is hard to deal with long Bash scripts if we don’t use the goto statement. Let’s understand a Bash script that works like the goto statement in Bash. Consider the following code in Bash. #!/bin/bash function goto { label=$1 cmd=$(sed -n "/$label:/{:a;n;p;ba};" $0 ...
Method 1: Using theifStatement and the[[Operator Theifstatement in Bash is used to perform conditional execution of commands based on the exit status of atestcommand. In this case, we can use the[[operator to perform a string comparison between the target string and the substring. ...