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Linux / UNIX: Find Out If a Directory Exists or Not

I've already written a small tutorial about finding out if a file exists or not under Linux / UNIX bash shell. However, couple of our regular readers like to know more about a directory checking using if and test shell command.

General syntax to see if a directory exists or not

[ -d directory ]
test directory
See if a directory exists or not with NOT operator:
[ ! -d directory ]
! test directory

Find out if /tmp directory exists or not

Type the following command:
$ [ ! -d /tmp ] && echo 'Directory /tmp not found'
$ [ -d /tmp ] && echo 'Directory found' || echo 'Directory /tmp not found'

Sample Shell Script to gives message if directory exists

Here is a sample shell script:

if [ $# -ne 1 ]
	echo "Usage: $0 {dir-name}"
	exit 1
if [ -d "$DIR" ]
	echo "$DIR directory  exists!"
	echo "$DIR directory not found!"

Linux/UNIX: Find Out If File Exists With Conditional Expressions

With the help of BASH shell and IF command, it is possible to find out if file exists or not on the filesystem. A conditional expressions (also know as "evaluating expressions") can be used by [[ compound command and the test ([) builtin commands to test file attributes and perform string and arithmetic comparisons.
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xrandr: Linux Resize / Set The Screen Size Quickly Via Command Line Options

Generally, I need to switch my Gnome screen size to 800x600 to watch TV via TV-Tunner card as my card supports max 800x600 resolution. For rest of my work I prefer to use 1024x768 pixels. You can create a shortcuts on the desktop to resize screen quickly:
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