Rename multiple files in Bash

damianpfister · 11-14-2009, 01:03 PM

Hi Everyone

I am trying to find a way of renaming a list of mp3 files in bash, so that letters are added to their names at the beginning.
For example SONG1.MP3 should become a.SONG1.MP3 and SONG2.MP3 b.SONG2.MP3

It is simple enough to change them to a all have a specific characteristic, such as different extension or even numbered rather than "lettered" at the front....but I cannot figure out how to get them into letters.

for x in *.mp3;do let i+=1; mv "$x" ${i}."${x}"; done

...this changes them to be

1.SONG1.MP3
2.SONG2.MP3

...and so on

How do I get

a.SONG1.MP3
b.SONG2.MP3

and so on?

Had thought about having two loops such as

for x in {a..z} and then for x in *.mp3 ....but I fear this will merely run through a..z for each file rather than just a single file before moving to the next letter.

Another thought was using an array...but again I am not sure how to put this into an effective loop.

Any suggestions?

lwasserm · 11-14-2009, 01:23 PM

How about using *.mp3 as the argument to your script and letting the shell then take care of assigning all mp3 files to $1, $2, etc. Then you can do something like

Code:

for letter in {a..z}; do
mv "$1" "$letter.$1"
shift
done

You'll have to add your own logic for dealing with more than 26 files.

ta0kira · 11-14-2009, 02:24 PM

Using {,{a..z}}{a..z} will give you 702 prefixes...
Kevin Barry

edit: Or 18278 with {,{,{a..z}}{a..z}}{a..z}. Maybe better as this, though:

Code:

echo {,{,{a..z}}{a..z}}{a..z} | tr ' ' '\n' | while read prefix; do #...

PTrenholme · 11-14-2009, 04:32 PM

If you use KDE, there's a nice app, krename, that you can use for "bulk" renaming of files.

damianpfister · 11-14-2009, 05:33 PM

Quote:

Originally Posted by lwasserm

How about using *.mp3 as the argument to your script and letting the shell then take care of assigning all mp3 files to $1, $2, etc. Then you can do something like

Code:

for letter in {a..z}; do
mv "$1" "$letter.$1"
shift
done

You'll have to add your own logic for dealing with more than 26 files.

Hmm....never thought of making it an argument to my script. So I was over-complicating it by trying to make it all fit inside a single script - ok...lesson learned.

Just put this to the test and it works a treat!
THANKS!

lwasserm · 11-15-2009, 08:30 AM

Your idea of using an array would work pretty well also. It could be done like this:

Code:

NAME=(*.mp3)
LETTER=({a..z})
N=0

for ((N=0;$N<${#names[*]};N++)); do
mv "${NAME[$N]}" "${LETTER[$N]}.${NAME[$N]}"
done

taOkira showed how to stack up sequences for more prefix combinations, thanks I didn't know you could do that.

You could also code the for loop to check the prefix letter for 'z' and change it to a longer prefix or however it needs to be done for your application.