How to rename file extension to lowercase?

Question

I know this question has been asked (and answered) before, but it seems my situation is unique, because I cannot have any of the solution to work.

Running, I need to rename all my photos from *.JPG to *.jpg.

Let's say I don't need recursive, just all the pictures in the same folder.

The problem I meet is this one:

mv: ‘P1010521.JPG’ and ‘p1010521.jpg’ are the same file

Same problem using rename, with that kind of command:

rename 's/\.JPG$/.jpg/' *.JPG
P1020558.JPG not renamed: P1020558.jpg already exists

score 14 · Accepted Answer · edited Apr 13 '17 at 12:24

14

It is really simple:

Rename to something else than the same value with different case
```
rename 's/\.JPG$/\.jpgaux/' *.JPG
```
Now rename that something else to .jpg back again, but lowercase this time
```
rename 's/\.jpgaux$/\.jpg/' *.jpgaux
```

Demo: http://paste.ubuntu.com/8853245/

Source: How to change extension of multiple files from command line? Thanks to Chakra!

edited Apr 13 '17 at 12:24

Community

1

answered Nov 06 '14 at 15:34

Lucio

19,191
32
112
191

score 2 · Answer 2 · answered Dec 19 '19 at 02:40

2

really easy with mmv:

sudo apt install mmv

mmv \*.JPEG \#1.jpeg

answered Dec 19 '19 at 02:40

sailfish009

235

score 2 · Answer 3 · edited Oct 15 '20 at 21:46

If αғsнιη is right in his comment, and I think he is, OP's problem is that a similarly named file already exists. If that is the case, the script will have to check if the targeted file name (lowercase) already exists, and (only) if so, rename the original file additionally (not only lowercase extension) to prevent the name error, e.g.

image1.JPG

to

renamed_image1.jpg

since image1.jpg would raise an error

If so, a python solution to rename could be:

#!/usr/bin/env python3
import os
import shutil
import sys
directory = sys.argv[1]
for file in [f for f in os.listdir(directory) if f.endswith(".JPG")]:
        newname = file[:file.rfind(".")]+".jpg"
        if os.path.exists(directory+"/"+newname):
                newname = "renamed_"+newname
        shutil.move(directory+"/"+file, directory+"/"+newname)

The script renames:

image1.JPG -> image1.jpg

but if image1.jpg already exists:

image1.JPG -> renamed_image1.jpg

###How to use

Copy the script into an empty file, save it as rename.py, make it executable and run it by the command:

<script> <directory_of_files>

score 1 · Answer 4 · answered Jan 20 '17 at 15:50

1

This works best I think, as perl supports running code in the regex

rename -n 's/(\.[A-Z]+$)/lc($1)/ge' *.*[A-Z]*

remove the -n to actually rename the files

answered Jan 20 '17 at 15:50

HeLi8

11
1

How to rename file extension to lowercase?

4 Answers4

Demo: http://paste.ubuntu.com/8853245/