How to Check If a File or Directory exists in Linux

osetc @ October 11, 2019 Bash Shell

When you writing a bash script, you may be need to check if a given file or directory exists or not. And this post will guide you how to if a file or directory exists or not in your Linux operating system. How do I test if a file exists using test command in your Linux system.

Test Command
Test If File Exists
Test If Directory Exists
Test If File Does Not Exist
Test If Multiple Files Exist

How to Check If a File or Directory exists in Linux1

Test Command

Test command can be used to check file types and compare values. Exit with the status determined by EXPRESSION.

The syntax of the Test command are as followss:

test EXPRESSION
test
[ EXPRESSION ]
[ ]
[ OPTION

Options:

-n STRING the length of STRING is nonzero
-z STRING the length of STRING is zero
-b FILE FILE exists and is block special
-c FILE FILE exists and is character special
-d FILE FILE exists and is a directory
-e FILE FILE exists
-f FILE FILE exists and is a regular file
-g FILE FILE exists and is set-group-ID
-G FILE FILE exists and is owned by the effective group ID
-h FILE FILE exists and is a symbolic link (same as -L)
-k FILE FILE exists and has its sticky bit set
-L FILE FILE exists and is a symbolic link (same as -h)
-O FILE FILE exists and is owned by the effective user ID
-p FILE FILE exists and is a named pipe
_{-r FILE} FILE exists and read permission is granted
-s FILE FILE exists and has a size greater than zero
-S FILE FILE exists and is a socket
-t FD file descriptor FD is opened on a terminal
-u FILE FILE exists and its set-user-ID bit is set
-w FILE FILE exists and write permission is granted
-x FILE FILE exists and execute (or search) permission is granted

Test If File Exists

If you want to check if a given file named mytest.txt located in /tmp directory exists, and you can use one of following statements in your bash script:

if [ -f /tmp/mytest.txt ]
then
echo "mytest.txt file exists"
fi

if test -f /tmp/mytest.txt 
then
echo "mytest.txt file exists"
fi

if [[ -f /tmp/mytest.txt ]]
then
echo "mytest.txt file exists"
fi

[ -f /tmp/mytest.txt ] && echo "mytest.txt file exists"

If you want to take another action while file does not exist, you can write it as below:

if [ -f /tmp/mytest.txt ]
then
    echo "mytest.txt file exists"
else
    echo "mytest.txt file does not exists"
fi

[ -f /tmp/mytest.txt ] && echo "mytest.txt file exists" || echo "mytest.txt file does not exists"

Test If Directory Exists

If you want to create a new file in a given directory in your bash script, and you need to make sure that that directory exists or not.

For example, you want check a directory /mytmp exists or not you can use:

if [ -d /mytmp ]
then
    echo "/mytmp directory exists"
fi

[ -d /mytmp ] && echo "/mytmp directory exists"

You can also use the test command to check directory exist or not, see below:

if test -d /tmp/mytest.txt 
then
    echo "mytest.txt file exists"
fi

Test If File or Directory Does Not Exist

If you only want to check file or directory does not exist firstly, and if true, then you can take some action. you can use the exclamation mark (!) logical operator in the test experssion in your bash script, see below:

[ !-f /tmp/mytest.txt ] && touch /tmp/mytest.txt

[ ! -d /mytmp ] && mkdir -p /mytmp

Test If Multiple Files Exist

If you need to test two or multiple files exist or not, and you can use:

if [ -f /tmp/mytest.txt && -f /tmp/mytest2.txt]
then
    echo "mytest.txt and mytest2.txt file exist"
fi

[ -f /tmp/mytest.txt && -f /tmp/mytest2.txt ] && echo "mytest.txt and mytest2.txt file exist"

Conclusion

You should know that how to check if a file or direcotry exists or not using test command in bash shell.

OSETC TECH