How do I change the extension of multiple files?

Question

I would like to change a file extension from *.txt to *.text. I tried using the basename command, but I'm having trouble on changing more than one file.

Here's my code:

files=`ls -1 *.txt`

for x in $files
do
    mv $x "`basename $files .txt`.text"
done

I'm getting this error:

basename: too many arguments Try basename --help' for more information

Answer 1

Straight from Greg's Wiki:

# Rename all *.txt to *.text
for f in *.txt; do 
    mv -- "$f" "${f%.txt}.text"
done

*.txt is a globbing pattern, using * as a wildcard to match any string. *.txt matches all filenames ending with '.txt'.

-- marks the end of the option list. This avoids issues with filenames starting with hyphens.

${f%.txt} is a parameter expansion, replaced by the value of the f variable with .txt removed from the end.

Also see the entry on why you shouldn't parse ls.

If you have to use basename, your syntax would be:

for f in *.txt; do
    mv -- "$f" "$(basename -- "$f" .txt).text"
done

Answer 2

Here's how I change all the file extensions in the current directory on Debian.

rename "s/oldExtension$/newExtension/" *.txt

(This is the Perl rename command, not the util-linux one. See Why is the rename utility on Debian/Ubuntu different than the one on other distributions, like CentOS?)

On MacOS, user Monkpit reports that they were able to use brew install rename to get this to work.

Answer 3

A simple command, rename from util-linux, will do that for you. It replaces every occurrence of "txt" with "text" in all files matching "*.txt":

rename txt text *.txt

Answer 4

rename "s/oldExtension/newExtension/" *.txt

Above works fine but limited to current directory. Try the command below, which is flexible with sub-directories. It will rename all .txt files under directory structure with a new extension.

find . -type f -name "*.txt" -exec rename 's/\.txt$/.newext/' '{}' \;

Answer 5

The answers here referencing s/oldExtension/newExtension/ are wrong. If you use s/txt/text/, you would convert footxt.txt to footext.txt, which is not what you want. Even if you use s/.txt/.text/, that would convert footxt.txt to fo.text.txt.

You have to use \. to match the period (. will match any character). And the trailing $ to match the end of the line. Only this will properly match the extension.

rename 's/\.txt$/.text/' *.txt

rename 's/\.old$/.new/' *.old

Answer 6

Reason #53 to switch to zsh:

zmv '(*).txt' '$1.text'

Answer 7

Based on the @Prince John Wesley answer, here is a simple bash script for changing all extensions of files in the current directory from ext1 to ext2. Also outputs names of the files being renamed.

#!/bin/bash
for f in *.$1
do
    [ -f "$f" ] && mv -v "$f" "${f%$1}$2"
done

Example usage (assuming the name of the script is change-ext):

change-ext ext1 ext2

Answer 8

for f in *.txt
do
    [ -f "$f" ] && mv "$f" "${f%txt}text"
done

Answer 9

let's say your files are scattered in various directory, Assuming that dirx is your parent directory, this can do the job using find:

for f in `find /dirx -iname '*.txt' -type f -print`;do  mv "$f" ${f%.txt}.text; done

Answer 10

On Ubuntu 18.04, the util-linux rename command is available as rename.ul. This worked for me:

rename.ul -o -v .oldext .newext *.oldext

Options:

• -o: don't overwrite preexisting .newext
• -v: verbose
• -n: dry run

For more info, see man rename.ul or rename.ul -h.

Answer 11

When you

do not have an extension for the source files

and target extension is .text you would do it this way -

for f in *; do mv -- "$f" "${f%.\*}.text"; done

Answer 12

This is what works for me:

find . -name '*.txt' -exec rename 's/\.txt$/.text/' \{} \;

Answer 13

In case you want to know what went wrong in your version: You used $files instead of $x in the basename command. So this should work (untested, though):

for x in *.txt
do
  mv "$x" "`basename "$x" .txt`.text"
done

Answer 14

Mmv (available in the main distributions repositories) is also very useful for renaming. Give the patterns in quotes and each glob element can be reproduced by #N:

mmv '*.txt' '#1.text'

Some more interesting, neat examples in the manual page:

Rename files ending in .html.en, .html.de, etc. to ending in .en.html, .de.html, etc.:

mmv '*.html.??' '#1.#2#3.html' 

Rename music files from <track no.> - <interpreter> - <song title>.ogg to <interpreter> - <track no.> - <song title>.ogg:

mmv '* - * - *.ogg' '#2 - #1 - #3.ogg' 

Answer 15

Nobody has shown using shell parameter expansion, which is the most basic, probably shell compliant, (and I believe most readable) way of doing this.

# by removing suffix 
for f in *.txt; do echo "$f" "${f%txt}text"; done

# by substitution
for f in *.txt; do echo "$f" "${f/%txt/text}"; done

# simply edit mv for echo after testing
# % searched for shortest string, %% is 'greedy' would search for longest
# if you have a basename, use basename*.txt

https://www.debuntu.org/how-to-bash-parameter-expansion-and-string-manipulation/
https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html