Linux / UNIX: Find Out If File Exists With Conditional Expressions in a Bash Shell

last updated June 9, 2018 in Howto, Linux, RedHat/Fedora Linux, Shell scripting, UNIX

With the help of BASH shell and IF command, it is possible to find out if a file exists or not on the filesystem. A conditional expression (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.

You can easily find out if a regular file does or does not exist in Bash shell under macOS, Linux, FreeBSD, and Unix-like operating system. You can use [ expression ], [[ expression ]], test expression, or if [ expression ]; then .... fi in bash shell along with a !operator. Let us see various ways to find out if a file exists or not in bash shell.

Syntax to find out if file exists with conditional expressions in a Bash Shell

The general syntax is as follows:
[ parameter FILE ]
OR
test parameter FILE
OR
[[ parameter FILE ]]
Where parameter can be any one of the following:

-e: Returns true value if file exists.
-f: Return true value if file exists and regular file.
-r: Return true value if file exists and is readable.
-w: Return true value if file exists and is writable.
-x: Return true value if file exists and is executable.
-d: Return true value if exists and is a directory.

Please note that the [[ works only in Bash, Zsh and the Korn shell, and is more powerful; [ and test are available in POSIX shells. Let us see some examples.

Find out if file /etc/passwd file exist or not

Type the following commands:
$ [ -f /etc/passwd ] && echo "File exist" || echo "File does not exist" $ [ -f /tmp/fileonetwo ] && echo "File exist" || echo "File does not exist"

How can I tell if a regular file named /etc/foo does not exist in Bash?

You can use ! operator as follows:
[ ! -f /etc/foo ] && echo "File does not exist"Exists
OR

#!/bin/bash
file="/.config/backup.cfg"
if [ ! -f "$file" ]
then
    echo "$0: File '${file}' not found."
fi

[[ example

Enter the following commands at the shell prompt:
$ [[ -f /etc/passwd ]] && echo "File exist" || echo "File does not exist" $ [[ -f /tmp/fileonetwo ]] && echo "File exist" || echo "File does not exist"

Find out if directory /var/logs exist or not

Type the following commands:
$ [ -d /var/logs ] && echo "Directory exist" || echo "Directory does not exist" $ [ -d /dumper/fack ] && echo "Directory exist" || echo "Directory does not exist"

[[ example

$ [[ -d /var/logs ]] && echo "Directory exist" || echo "Directory does not exist" $ [[ -d /dumper/fake ]] && echo "Directory exist" || echo "Directory does not exist"

Are two files are the same?

Use the -ef primitive with the [[ new test command:

## first compare /etc/resolv.conf with /etc/resolv.conf ##
[[ /etc/resolv.conf -ef /etc/resolv.conf ]] && echo "Same files" || echo "Noop"
 
## now compare /etc/resolv.conf with /etc/passwd ##
[[ /etc/resolv.conf -ef /etc/passwd ]] && echo "Same files" || echo "Noop"

How to check if a file exists in a shell script

You can use conditional expressions in a shell script:

#!/bin/bash
FILE="$1"
 
if [ -f "$FILE" ];
then
   echo "File $FILE exist."
else
   echo "File $FILE does not exist" >&2
fi

Save and execute the script:
$ chmod +x script.sh $ ./script.sh /path/to/file $ ./script.sh /etc/resolv.conf
To check if a file exists in a shell script regardless of type, use the -e option:

#!/bin/bash
FILE="$1"
 
[ "$FILE" == "" ] && { echo "Usage: $0 filename"; exit 1; }
if [ -e "$FILE" ];
then
   echo "File $FILE exist."
else
   echo "File $FILE does not exist" >&2
fi

You can use this technique to verify that backup directory or backup source directory exits or not in shell scripts. See example script for more information.

A complete list for file testing in bash shell

From the test command man page:

[ Expression ]	Meaning
`-b filename`	Return true if filename is a block special file.
`-c filename`	Return true if filename exists and is a character special file.
`-d filename`	Return true filename exists and is a directory.
`-e filename`	Return true filename exists (regardless of type).
`-f filename`	Return true filename exists and is a regular file.
`-g filename`	Return true filename exists and its set group ID flag is set.
`-h filename`	Return true filename exists and is a symbolic link. This operator is retained for compatibility with previous versions of this program. Do not rely on its existence; use -L instead.
`-k filename`	Return true filename exists and its sticky bit is set.
`-n filename`	Return true the length of string is nonzero.
`-p filename`	Return true filename is a named pipe (FIFO).
`-r filename`	Return truefilename exists and is readable.
`-s filename`	Return true filename exists and has a size greater than zero.
`-t file_descriptor`	Return true the filename whose file descriptor number is file_descriptor is open and is associated with a terminal.
`-u filename`	Return true filename exists and its set user ID flag is set.
`-w filename`	Return true filename exists and is writable. True indicates only that the write flag is on. The file is not writable on a read-only file system even if this test indicates true.
`-x filename`	Return true filename exists and is executable. True indicates only that the execute flag is on. If file is a directory, true indicates that file can be searched.
`-z string`	Return true the length of string is zero.
`-L filename`	Return true filename exists and is a symbolic link.
`-O filename`	Return true filename exists and its owner matches the effective user id of this process.
`-G filename`	Return true filename exists and its group matches the effective group id of this process.
`-S filename`	Return true filename exists and is a socket.
`file1 -nt file2`	True if file1 exists and is newer than file2.
`file1 -ot file2`	True if file1 exists and is older than file2.
`file1 -ef file2`	True if file1 and file2 exist and refer to the same file.

Conclusion

You just learned how to find out if file exists with conditional expressions in a Bash shell. For more information type the following command at shell prompt or see test command in our wiki or see bash man page here:
bash(1),test(1)

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

37 comment

loony says:
October 27, 2007 at 2:17 pm
For me the if statement only works when using the FILE var with quotes like this:
if [ -f “$FILE” ];
Reply
aditya says:
May 12, 2008 at 5:21 am
script was very userful
Reply
Mehdi Anis says:
December 3, 2008 at 4:49 pm
I need to check a file on daily basis that is created by anotehr process. The file format is:
DataFile_MMDDYYYY.csv
So, I need to get today’s date in MMDDYYYY format, concate that with a string variable, FileName = “DataFile_” + DatePart + “.csv”
Then look for that FileName file if exists then run a command (sas sendemail.sas).
How can I achieve that? Thanks.
Reply
thant says:
December 8, 2008 at 4:57 pm
DatePart=`date ‘+%m%d%Y`
FileName =DataFile_${DatePart}.csv
Reply
Don Petrus says:
January 14, 2009 at 3:03 pm
Hello Volks:
I would like to look for a File: if it exists – AND – itÂ´smaller (lt/gt) than 1000000, then … echo ” File too small” , return 1 … and so on:
#!/bin/bash
FILE=nec2.txt
if -f [ “$FILE” ] && -f [ “$FILE” -lt 1000000 ] ;
then
echo “File $FILE too small”
else
echo “File $FILE does not exists”
fi
-rw-rw—- 1 cas lokus 31626 2008-12-15 14:00 xnec2.txt
I use linux 2.4.21-278-smp
Can you please help there ? Pleas reply to donpetrus@hotmail.com
Many thanks in advance – Petrus
Reply
Bram says:
April 6, 2009 at 9:02 am
Bash knows the NOT procedure for IF. So No ELSE would be used. watch the !
```
#!/bin/bash
FILE=$1
if [ ! -f $FILE ];
then
   echo "File $FILE does not exists"
fi
```
Reply
Zach says:
October 1, 2009 at 8:52 pm
I just hacked this together. I plan to use it for my other scripts. The exit statements make the script exit with a 0 (bash standard for successful completion) or a 1 (non-zero is the bash standard for a failed action)
#!/bin/bash
FILE=$1
if [ -f $FILE ];
then
exit 0
else
exit 1
fi
Reply
1. Satyajit Sahoo says:
  September 20, 2012 at 9:10 am
  Just this much will do,
  #!/bin/bash
  FILE=$1
  [[ -f $FILE ]]
  Reply
Rajee says:
October 9, 2009 at 10:06 am
How to check some set of files in the following directory and do the process.
my statement following is not working: pls explain
if [ -f “$ROOT/abc/files/CUST*” ]; then
echo “inside customer file exists”
else
echo “No customer file exists”
fi
CUST is the post fix of the files, expected to have more than 1 file on some days.
Reply
Fred says:
November 17, 2009 at 1:31 pm
For me, it only works without variables, like
if [ -f /home/user/hey.jpg ]; then
….
else
….
fi
Worth trying.
Reply
Debbie says:
November 24, 2009 at 7:41 pm
I want to test if any file ending in *.DATGO exists.
Do you always have to use the exact name of the file?
Reply
krishna says:
January 24, 2010 at 1:21 pm
I need the shell script to check whether the file exist or not
and whether the format of the file is .dat or not
expecting the help ASAP…pls
Reply
1. Prabhu says:
  April 4, 2017 at 3:42 pm
  Did someone figure this out?
  Reply
  1. cyberciti says:
    May 2, 2017 at 10:05 am
    Take a look at file command. It can determine file type.
    Reply
amit says:
March 11, 2010 at 5:09 pm
the only thing i can say is that –
if statement does’nt allow wild card, you have to think a work around for this
Reply
Anthony Youngman says:
May 28, 2010 at 8:40 pm
ls D
blah blah blah
drwx—— Program Files
if -d D/Program Files returns FALSE
It would be nice if I could find some way of successfully testing for names with spaces 🙁
Cheers,
Wol
Reply
1. Sergani says:
  August 2, 2011 at 1:26 am
  Try ls -1D (that’s ls -‘ONE’ -D)
  Reply
Jasper says:
August 2, 2010 at 10:57 am
Hi,
I need to check if a file with the current date exists in a folder. How would I do that?
Reply
Betulino says:
August 12, 2010 at 8:06 am
Hi,
I have /media/USBDisk0 and that the mount point for my USBDisk.
And a hard link named /media/TheData/Data -> /media/USBDisk0/Data
When the USB is mounted, the hard link is OK, but If something fail, the hard link is broken…. Can use the if to test the hard link?
Reply
sonal says:
February 7, 2011 at 6:34 am
i need to check all the files in the current directory and display them.how can i do this?
Reply
1. Sergani says:
  August 2, 2011 at 1:30 am
  cd /path/to/directory
  for i in $(ls -1 *)
  do
  if [ -f $i ] ; then
  ll $i
  else
  echo “$i is not a file”
  fi
  Reply
Lalit Mohan says:
March 7, 2011 at 6:35 am
I want to check file that i fetching is complete or not, if file is still copying than wait for few minutes, can this things possible, Reply me Please!!!
Reply
Ked says:
June 28, 2011 at 1:05 pm
That was a great help, I needed a script to check if the .parentlock file was present in the Thunderbird profile directory and then delete it if it was.
Worked first time 🙂
Reply
1. Sergani says:
  August 2, 2011 at 1:32 am
  you could also have done the following:
  find /home/username/thunderbird-directory/ -iname .parentlock -ok rm {} ;
  it’ll find the file and attempt to remove it, but will ask you first… if you need it to remove it right away, replace -ok with -exec
  Reply
Ravi Theja says:
September 13, 2011 at 8:05 pm
if [ -e filename ] works for me and checks fine ONLY when I’m logged in as a power broker. It doesn’t test when I log in as a normal user or call the script from a different scheduling tool.
Please help me ASAP
Reply
chey says:
December 2, 2011 at 3:41 pm
Thanks for the script, it was very useful.
Reply
Rahul says:
May 14, 2012 at 7:20 pm
i need shell script where the i need to connect from one server to another server…
and check for file *.mediate.log in path /home/apps/ and if found it need to execute a script prescript.sh in the same path and return a status to the server…and if the files doesn’t exist it shud return another status…and if the job fails becoz of any resin it need to return another status…
Can you please help me with this ASAP…very urgent
Reply
srini says:
September 5, 2013 at 9:06 am
I have a file with date and time. but I want to check with date part only file exist or not without changing the file.
Can any one pleae help me.
Reply
1. Manoj says:
  December 3, 2013 at 4:22 pm
  Can we find content in file with if condition, for an example if ‘abc’ is there in xyz file or not.
  Regards,
  Manoj
  Reply
Santosh says:
July 31, 2014 at 11:20 am
Not Working for me for the below code
#!/bin/bash
FILE=$1
if [ ! -f $FILE ];
then
echo “File $FILE does not exists”
fi
Reply
1. newton says:
  August 12, 2015 at 4:38 am
  How are you running the script?
  Reply
Shahid says:
October 15, 2014 at 2:25 pm
I need to check if in
1.example1.sh test.log exists
if 1 is yes then execute 2 else execute 5
2. get the current date from test.log file
3. get current system date
4. if date in step 2 + 1 day <=date in step 3 then step 5 else step 6
5. execute example2.sh
6.end
example2.sh
writes to test.log
and also contains current date and current time
Reply
Ikem says:
February 3, 2015 at 4:56 pm
Very useful is also the test parameter “-s” which checks if a file exists and has a size greater then zero.
Reply
jh says:
January 22, 2016 at 8:05 pm
“File does not exists” should be “File does not exist” right?
Reply
kian says:
June 3, 2016 at 6:09 am
why use >&2
Reply
sharath says:
June 22, 2016 at 10:15 am
i want to check if the file exists in a folder:
if exists(delete the file in the folder)
else
create a new file in the same name.
I tried the above codes which dint work for me.. any help would be of great help..
Reply
Naveen DN says:
December 15, 2017 at 8:54 am
very useful,,,thanks a lot.
Reply

Syntax to find out if file exists with conditional expressions in a Bash Shell

Find out if file /etc/passwd file exist or not

How can I tell if a regular file named /etc/foo does not exist in Bash?

[[ example

Find out if directory /var/logs exist or not

[[ example

Are two files are the same?

How to check if a file exists in a shell script

A complete list for file testing in bash shell

Conclusion

Posted by: Vivek Gite

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