As the title says, how can I change the extension of every file in a directory in Ubuntu? I've seen some examples use rename etc etc but I get an error (Unable to locate package rename) and it's not accessible through apt-get.

As an additional, I don't actually know the original file type! It's data that's been copied from the file system of Hadoop to the local drive and I need them all to be in .txt format.

If it makes a difference, I'm running Ubuntu 12.04 in Oracle Virtual Box

Edit: Output of: ls -l /usr/bin/rename /etc/alternatives/rename

amartin24@ubuntu-amartin24:~/TwitterMining/JSONTweets$ ls -l /usr/bin/*rename* /etc/alternatives/rename
ls: cannot access /etc/alternatives/rename: No such file or directory
-rwxr-xr-x 1 root root 10392 Mar 30  2012 /usr/bin/rename.ul

6 Answers 6


The rename command is already installed, you don't need to add anything else.

rename takes Perl code as its first argument. Most concrete use cases of renaming consist of a regexp replacement: s/REGEXP/REPLACEMENT/. To remove the existing extension, replace everything starting at the last . character.

rename 's/\.[^.]*$/.txt/' /path/to/directory/*

If your files have no extension (no . in their name), you can either use $ (which matches the end of the file name) as the regexp, or append .txt to the name.

rename '$_ = "$_.txt"'  /path/to/directory/*

This doesn't change the content of the files, it only renames them. If your data isn't in the format you want, that's a completely unrelated problem.

  • Didn't know about rename. This is definitely more elegant than my solution. +1 Aug 15, 2013 at 18:31
  • I'd love to use this solution, but when I run it it says "rename: command not found". What am I doing wrong? Aug 15, 2013 at 20:39
  • @AndrewMartin That's really weird. Oh, that command is part of the perl package, which may no longer be installed by default on server installations. But even if perl isn't installed, you should have a rename command with a different syntax (that isn't as useful for this question) instead. Aug 15, 2013 at 20:49
  • I tried installing perl, but apparently it's already installed. Do you have any other suggestions on how to get rename working? Aug 15, 2013 at 22:36
  • @AndrewMartin Something's wrong with your system. What does ls -l /usr/bin/*rename* /etc/alternatives/rename show? What about type rename perl and echo $PATH? Aug 15, 2013 at 22:38

You could cd to the directory in question and execute something similar to this:

find -L . -type f -name "*.oldextension" -print0 | while IFS= read -r -d '' FNAME; do
    mv -- "$FNAME" "${FNAME%.oldextension}.newextension"

Or if the files don't have any extension at all:

find -L . -type f -print0 | while IFS= read -r -d '' FNAME; do
    mv -- "$FNAME" "${FNAME%}.newextension"

In your case you would have to replace newextension with txt.

Someone more proficient with bash might be able to break this down better. Please feel free to edit my answer in that case.

Original description:

1) It will rename just the file extension (due to use of ${FNAME%.so}.dylib). All the other solutions using ${X/.so/.dylib} are incorrect as they wrongly rename the first occurrence of .so in the filename (e.g. x.so.so is renamed to x.dylib.so, or worse, ./libraries/libTemp.so-1.9.3/libTemp.so is renamed to ./libraries/libTemp.dylib-1.9.3/libTemp.so - an error).

2) It will handle spaces and any other special characters in filenames (except double quotes).

3) It will not change directories or other special files.

4) It will follow symbolic links into subdirectories and links to target files and rename the target file, not the link itself (the default behaviour of find is to process the symbolic link itself, not the file pointed to by the link).


Bash rename extension recursive - stackoverflow, answered by aps2012.

  • That's correct, but a lot more complex than it needs to be. Aug 15, 2013 at 18:00
  • As I couldn't get rename working, I went with this. A little longer, but works perfectly. Thanks for putting the time into answering this. Aug 15, 2013 at 22:39

I think you can use this simple bash script


for file in *
  mv -- "${file}" "${file%.*}.txt"

this script works for both cases with extension or without


GUI solution


There is a really easy to use and powerful GUI tool in the Ubuntu Software Center to rename batches of files, pyRenamer.


sudo apt-get install pyrenamer


(source: ubuntu.com)


enter image description here

  • Thanks for your answer. Could you walk us through on how you would use pyrename to change the extension of all files in a directory? I.e. what patterns would you use? Aug 15, 2013 at 18:47
  • Thanks for this, but I should have specified that I can't use a GUI (accessing a remote VM without GUI available) Aug 15, 2013 at 20:40

I have this script. I know it is not dummy-prove, namely while handling files with spaces. That is why I run detox at the begining.

#   detox * 
# uncomment if you want to get rid of spaces and funny characters
    script=$(basename $0)
if  [ -z "$1" ] || [ "$1" == "-h" ] || [ "$1" == "--help" ]; then
    echo "Script for adding an extension to files without extension"
    echo "---------------------------------------------------------"
    echo -e "\n Usage:"
    echo -e "   $script extension\n"
    echo -e "Exampli gratia: \n The command:"
    echo "      $script txt"
    echo -e "   will rename:\n      FileWithoutExtension -> FileWithoutExtension.txt\n"

for file in $(ls -p -I '*.*' | grep -v '/$') # excludes direcotires
    mv -iv "$file" "$file.$1"

If you have a bunch of files without extensions at all (like ./out_1, ./out_2, out_3, ... ) :

ls | xargs -i{} mv {} {}.YOUR_EXTENSION_HERE


ls | xargs -i{} mv {} {}.md

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