Bash Scripting – Else If Statement
In this article, we will discuss how to write a bash script for the Else If statement.
Conditional statements: The statements that perform specific functions based on certain conditions are called conditional statements. In bash scripting, we have several conditional statements like IF, IF-ELSE, IF-ELSE-IF, etc. Every statement has its way of working and according to the need, we use them.
This statement is used when there is a need to check only conditions. If the condition founds to be true then the statement was written inside the if block will get executed.
if (condition) then statement fi
if [ 15 -gt 10 ] then # If variable less than 10 echo "a is greater than 10" fi
This program will check the condition, whether 15 is greater than 10 or not. If 15 is greater than 10, the statement written inside the IF block will get printed on the screen.
a is greater than 10
As seen in the If statement, If the condition is true, the IF statement block gets executed but if the condition is false nothing is returned or executed. If we want the program to perform certain action after the IF statement condition is false, we use the ELSE statement after the If statement.
if [condition ] then If statement else ELSE statement fi
- If the condition is true: the IF statement will get executed.
- If the condition is false: the ELSE statement will get executed.
if [ 5 -gt 10 ] then # If variable less than 10 echo "number is greater than 10" else echo "number is less than 10" fi
number is less than 10
ELIF (ELSE IF) statement
ELIF is the keyword used for the ELSE IF statement in bash scripting. If in a loop if more than two conditions exist which can not be solved only by using IF-ELSE statement then ELIF is used. Multiple ELIF conditions can be defined inside one if-else loop.
if [ condition1 ] then statement1 elif [ condition2 ] then statement2 elif [condition3 ] then statement3 else statement_n fi
#!/bin/bash # Initializing the variable a=20 if [ $a < 10 ] then # If variable less than 10 echo "a is less than 10" elif [ $a < 25 ] then # If variable less than 25 echo "a is less than 25" else # If variable is greater than 25 echo "a is greater than 25" fi
a is greater than 25
If one or more than one conditional statement is written inside another statement, this is called nested statements like IF statements inside another IF statement.
Syntax (Nested IF):
If [condition] then if [condition_2] then statement_1 fi fi
#!/bin/bash #Initializing the variable if [ 12 -gt 10 ] then if [ 12 -gt 15] then echo "number is greater than 15" else echo "number is less than 15" fi fi
number is less than 15