What is the good way to add file extension ".jpg" to extension-less files with bash?
10 Answers
# Strip .jpg from all filenames
for f in *.jpg; do mv "$f" "${f%.jpg}"; done
# Add .jpg to all filenames (even those with .jpg already)
for f in *; do mv "$f" "$f.jpg"; done
# Add .jpg to all filenames...unless they are already .jpg
for f in *; do case "$f" in *.jpg) echo skipped $f;; *) mv "$f" "$f".jpg; esac; done
# Add .jpg to all filenames...unless they already have a . extension
for f in *; do case "$f" in *.*) echo skipped $f;; *) mv "$f" "$f".jpg; esac; done
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10second one is perfect for renaming extensionless files! thanks! Commented Sep 9, 2014 at 3:33
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5second one adds an extension on all files, not just extensionless ones– JeffCommented Mar 24, 2015 at 15:55
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6just as a note
"${f%.jpg}"
is bash shell string manipulation. ` ${string%substring}` Deletes shortest match of $substring from back of $string.– JichaoCommented Aug 28, 2015 at 19:36 -
2Warning: If you have a folder with mixed extensions, know that the above adds
.jpg
to even normal files. Commented Oct 27, 2016 at 23:51 -
1Can we check if its already ended with
.jpg
? to prevent adding additional.jpg
to the end– alperCommented Sep 29, 2021 at 14:01
You can use rename:
rename 's/(.*)/$1.jpg/' *
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3which version of rename are you using? Mine has different arguments:
rename from to file...
Commented May 24, 2011 at 17:31 -
1
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3This works great with the rename included in Ubuntu (and so I'm guessing all Debian based distros), much less verbose than jm666's answer. Commented Jun 10, 2012 at 10:59
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1Beware that there isn't a single
rename
tool: oylenshpeegul.typepad.com/blog/2011/12/… Commented Nov 18, 2021 at 17:02
Another way - without loops
find . -type f -not -name "*.*" -print0 |\
xargs -0 file |\
grep 'JPEG image data' |\
sed 's/:.*//' |\
xargs -I % echo mv % %.jpg
Breakdown:
- find all files without extension
- check the file type
- filter out only JPG files
- delete filetype info
- xargs run the "mv" for each file
the above command is for dry run, after it you should remove the "echo" before mv
EDIT Some people suggesting that here is needed "Wrap path arguments in quotes; avoids argument splitting on paths with spaces".
Usually, this recommendation is true, in this case isn't. Because, here the %
is got replaced not by shell expansion but by the xargs
internally (directly), so the %
will be substituted correctly even with spaces in filenames.
Simple demo:
$ mkdir xargstest
$ cd xargstest
# create two files with spaces in names
$ touch 'a b' 'c d'
$ find . -type f -print
./c d
./a b
# notice, here are spaces in the above paths
#the actual xargs mv WITHOUT quotes
$ find . -type f -print | xargs -I % mv % %.ext
$ find . -type f -print
./a b.ext
./c d.ext
# the result is correct even in case with spaces in the filenames...
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You can put this into a loop and this xargs are superfluous. I like Ryan's answer better in this situation.– LuciusCommented May 24, 2011 at 19:51
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1@Lucius - btw, the question want "extensionless" files - so Ryan should find only those...– clt60Commented May 24, 2011 at 20:12
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@jm666 hey! how do I modify your code snippet to rename all extensionless files in a folder to their respective extensions. (I am detecting correct extensions by file -b $filename command.) Commented Jan 10, 2016 at 16:44
Simple, cd to the directory where your files are and:
for f in *;do mv $f $f.jpg;done
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For some reason this works for me, but Seth's solution with quotes doesn't. (OSX Mountain Lion bash)– delroccoCommented Dec 18, 2016 at 14:36
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5Would be better if used
for f in *;do mv "$f" "$f".jpg;done
to support spaces in filenames.– HritikCommented Jun 22, 2017 at 17:09 -
Thanks for this elegant and simple solution -- I have landed on this answer multiple times, but can't seem to memorize it. #dejavu Commented Jan 30, 2019 at 18:11
dry run:
rename -n s/$/.jpg/ *
actual renaming:
rename s/$/.jpg/ *
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Beware that there isn't a single
rename
tool: oylenshpeegul.typepad.com/blog/2011/12/… Commented Nov 18, 2021 at 17:03
find . | while read FILE; do if [ $(file --mime-type -b "$FILE") == "image/jpeg" ]; then mv "$FILE" "$FILE".jpg; fi; done;
In my case i was not aware of the filetype so i used the mv command with the help of the file command to examine and possibly find the file type. This solution might not be perfect for all files since the file command might not recognize the filetype but it worked mostly good for me.
for f in *; do ext=$(file $f | awk '{print $2;}'); mv -n "$f" "$f.$ext"; done
The use of awk is to strip the second word of the string returned from the command file that is actually the extension.
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handles jpg and png automatically. used it and works - thanks a lot! Only now extensions are CAPS. small problem though :)– krivarCommented Jul 14, 2020 at 13:12
rename --dry-run * -a ".jpg" # test
* -a ".jpg" # rename
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--dry-run
and-a
are not available in my version ofrename
. If this is specific to some architecture it should be specified. Commented Apr 9, 2017 at 9:59 -
1As @FernandoCésar alludes to, there isn't a single
rename
tool, so the syntax may vary in different systems. See oylenshpeegul.typepad.com/blog/2011/12/… for more information. Commented Nov 18, 2021 at 17:04
You can use move multiple files. I am a maintainer of this project. The syntax is simple.
mmf files*
It will open your $EDITOR with all files names, or vim by default and you can simply highlight the end of all file names using Ctrl+v+G in vim , save the file,quit and that it , all your files are renamed
Ryan Li
The correct syntax for adding a file extension to multiple files within a directory which do not have a file extension is
find . | while read FILE; do if [[ -n `file --mime-type "$FILE" | grep 'message/rfc822'` ]]; then mv "$FILE" "$FILE".eml; fi; done;
mv "${file}" "${file}.jpg"
?