if...else...fi in Linux Shell Script
By: Dorris in Linux Tutorials on 2011-01-15
In Linux shell script, if...else...fi
is used to conditionally execute statements based on a condition.
The basic syntax for if...else...fi
is:
if condition then statements else statements fi
Here, the condition
is evaluated and if it is true, the statements within the then
block are executed, otherwise the statements within the else
block are executed.
For example, consider the following script that checks whether a number is even or odd:
#!/bin/bash echo "Enter a number:" read num if (( num % 2 == 0 )) then echo "$num is even." else echo "$num is odd." fi
In this script, the read
command is used to read a number from the user. Then, an if
statement is used to check whether the number is even or odd. If the number is even, the echo
command within the then
block is executed, otherwise the echo
command within the else
block is executed.
Note that the ((...))
syntax is used to perform arithmetic operations and the -eq
operator is used to compare two numbers for equality.
Add Comment
This policy contains information about your privacy. By posting, you are declaring that you understand this policy:
- Your name, rating, website address, town, country, state and comment will be publicly displayed if entered.
- Aside from the data entered into these form fields, other stored data about your comment will include:
- Your IP address (not displayed)
- The time/date of your submission (displayed)
- Your email address will not be shared. It is collected for only two reasons:
- Administrative purposes, should a need to contact you arise.
- To inform you of new comments, should you subscribe to receive notifications.
- A cookie may be set on your computer. This is used to remember your inputs. It will expire by itself.
This policy is subject to change at any time and without notice.
These terms and conditions contain rules about posting comments. By submitting a comment, you are declaring that you agree with these rules:
- Although the administrator will attempt to moderate comments, it is impossible for every comment to have been moderated at any given time.
- You acknowledge that all comments express the views and opinions of the original author and not those of the administrator.
- You agree not to post any material which is knowingly false, obscene, hateful, threatening, harassing or invasive of a person's privacy.
- The administrator has the right to edit, move or remove any comment for any reason and without notice.
Failure to comply with these rules may result in being banned from submitting further comments.
These terms and conditions are subject to change at any time and without notice.
- Data Science
- Android
- React Native
- AJAX
- ASP.net
- C
- C++
- C#
- Cocoa
- Cloud Computing
- HTML5
- Java
- Javascript
- JSF
- JSP
- J2ME
- Java Beans
- EJB
- JDBC
- Linux
- Mac OS X
- iPhone
- MySQL
- Office 365
- Perl
- PHP
- Python
- Ruby
- VB.net
- Hibernate
- Struts
- SAP
- Trends
- Tech Reviews
- WebServices
- XML
- Certification
- Interview
categories
Related Tutorials
smskannel SMS gateway run in background
Running jar files in background in ssh window
Install and configure Memcached in linux
Can't locate ExtUtils/MakeMaker.pm in @INC ...
Could not open '': No such file or directory at lib/ExtUtils/MM_Unix.pm line 2697
make: Nothing to be done for `all'.
How to burn your CD / DVD ISO image using Nero Burning ROM (Ahead Software) on Windows
How to burn your CD / DVD ISO image using Media Creator (Adaptec/Roxio) on Windows
How to burn your CD / DVD ISO image using Nero Express (Ahead Software) on Windows
How to burn your CD / DVD ISO image using k3b on CentOS
Comments