Add extension to a list of files

Question

I am trying to determine a perl method to add an extension to a list of files. I can already rename a list of files with a certain extension to some other extension, but I need to be able to do this for any file name, whether or not it already has an extension.

For example, I have a list of files such as:

file1
file2
file3
ps.dir

And I want to rename them ALL to filename.extension:

file1.bad
file2.bad
file3.bad
ps.dir.bad

Answer 1

At the shell, if you've got the Perl rename installed (sometimes called prename):

rename -v 's/$/.bad/' *

If you have too many files for the shell * glob to handle them all you can mix'n'match with find like this (also replace + with \; if necessary):

find . -maxdepth 1 -exec rename -v 's/$/.bad/' {} +

For Perl, just use move from a standard module:

use File::Copy;
for (<*>) { move($_, "$_.bad"); }

Answer 2

Assuming no spaces in the file names:

for file in *; do mv "${file}" "${file}.bad"; done

Answer 3

[ ! . -sf / ] &&
mkdir ../bad  &&
pax  -rwls/$/.bad/ . ../bad

That will create a hardlink mirror of . in ../bad. Every file rooted in . will afterward also be found in ../bad but by a name with the appendix .bad. If the new tree satisfies, remove the current tree and mv the ../bad tree over it.