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How to use Condition if file or directory exists on Bash Script on Ubuntu 22.04

To Use Condition If A File Or Directory Exists On Bash Script On Ubuntu 22.04

Introduction:

By using bash script you can easily find out if a regular file does or does not exist in Bash shell. The -d flag tests whether the provided name exists and is a directory. To test for regular files instead, we can use the -f flag. To test for both files and directories, we can use the -e flag.

Procedure:

Step 1: Check the OS version by using the below command

root@linuxhelp:~# lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 22.04.3 LTS
Release:	22.04
Codename:	jammy

Step 2: Create a file by using Vim editor by using the below command

root@linuxhelp:~# vim test.sh
Add the following lines in the file
#!/bin/bash
[ -f /etc/resolve.conf ] &&
echo "File exists" ||
echo "File does not exists"

Step 3: Now give execute permission by using the following command

root@linuxhelp:~# chmod +x test.sh

Step 4: Run the script by using the below command

root@linuxhelp:~# ./test.sh
File does not exist

Step 5: Change the line in the file

root@linuxhelp:~# vim test.sh
[ -f /etc/resolv.conf ] &&

Step 6: Again run the script by using the below command

root@linuxhelp:~# ./test.sh
File exit

Step 7: Now search for the directory, For that edit the file by using the below command

root@linuxhelp:~# vim test.sh
Add the lines in the file
#!/bin/bash
[ -d /var/logs ] &&
echo "Directory exist" ||
echo "Directory does not exist"

Step 8: Run the script by using the below command

root@linuxhelp:~# ./test.sh 
Directory does not exist

Step 9: Change the line in the file by using the below command

root@linuxhelp:~# vim test.sh
[ -d /var/log ] &&

Step 10: Run the script by using the below command

root@linuxhelp:~# ./test.sh 
Directory is  exist

Step 11: Now use the if condition in the file to that edit the file

root@linuxhelp:~# vim test.sh
#!/bin/bash
FILE="$1"
if [ -f "$FILE" ]
then
        echo "File $FILE exist"
else
        echo "$FILE does not exist" >&2
fi

Step 12: Now run the script with an argument

root@linuxhelp:~# ./test.sh /etc/passwd
File /etc/passwd exist

Step 13: Again run the script with a different argument

root@linuxhelp:~# ./test.sh /etc/passws
/etc/passws does not exist

Conclusion:

We have reached the end of this article. In this guide, we have walked you through the steps required to use Condition if a file or directory exists on Bash Script on Ubuntu 22.04. Your feedback is much welcome.

Tag : Bash-scripting Ubuntu Shell Script
FAQ
Q
How to read the value in Bash?
A
To read the Bash user input, we use the built-in Bash command called read.
Q
How do I check if a file exists in Bash?
A
if test -f /path/to/file; then echo "File exists." fi. To check whether a file does not exist
Q
How do I exit a Bash script?
A
We use exit to exit from a Bash script.
Q
What is the first line of the bash script?
A
The first line (/bin/bash) is used in every bash script.
Q
What are bash scripts used for?
A
A bash script is a file containing a sequence of commands that are executed by the bash program line by line. It allows you to perform a series of actions, such as navigating to a specific directory, creating a folder, and launching a process using the command line.