Rename files in the local folder adding a prefix or suffix

Question

I have many files in a folder and I want to add either prefix or a suffix (not both) to them. I checked here and found out I can use

for filename in *.jpg; do mv "$filename" "prefix_$filename"; done;

to add a prefix to all files ending in .jpg (and if I remove the .jpg, it will add the prefix to all the files in the current folder).

However, I'd like to be able to

• Add a sufix (that is, rename filename.ext to filename.whatever.ext),
• Check if the prefix or suffix is already present and then skip,
• Create an alias that accepts arguments such as addprefix whatever *.ext or addsufix whatever *.*

Answer 1

If you're using bash, then this one-liner can do it for you (assuming you have the variables $prefix, $suffix and $extension readily available)

mv "$filename" "$prefix${filename%.$extension}$suffix.$extension"

You could have your scripts be like this

#!/bin/bash
# Usage: addprefix <prefix> <files>

prefix=$1
shift
for f in "$@"
do
  mv "$f" "$prefix$f"
done

and

#!/bin/bash
# addsuffix <suffix> <files>

suffix=$1
shift
for f in "$@"
do
  extension=${f##*.}
  if [ -z $extension ]; then
    mv "$f" "$f$suffix"
  else
    mv "$f" "${f%.$extension}$suffix.$extension"
  fi
done

Answer 2

There's a Perl rename command that should do the trick. Beware though: there are several different commands called rename, so make sure you have got the Perl script that expects a perlexpr as its argument. This is the rename command provided by the perl package on Debian and derivatives (Ubuntu, Mint, …), but not on other distributions which may have a different utility called rename.

martin@martin ~/test % touch a.txt
martin@martin ~/test % touch b.txt
martin@martin ~/test % rename 's/^(prefix)?/prefix/' *.txt
martin@martin ~/test % ll
insgesamt 0
-rw-rw-r-- 1 martin martin 0 Sep 19 23:56 prefixa.txt
-rw-rw-r-- 1 martin martin 0 Sep 19 23:56 prefixb.txt
martin@martin ~/test % rename 's/^(prefix)?/prefix/' *.txt
martin@martin ~/test % ll
insgesamt 0
-rw-rw-r-- 1 martin martin 0 Sep 19 23:56 prefixa.txt
-rw-rw-r-- 1 martin martin 0 Sep 19 23:56 prefixb.txt

As you can see, it's idempotent - it won't add the prefix again when you call it multiple times.

It works by either replacing the (zero-length) start of the strings (^) or the start followed by an optional prefix string with prefix.

I'll leave encapsulating this in either a shell script or a shell function as an exercise for you :)

Postfix is a bit harder though, because you have to figure out what part of the filename constitutes the extension...

Answer 3

With zsh:

autoload zmv # in ~/.zshrc
zmv '(*~*suffix).ext' '${1}suffix.ext'

~ is the globbing operator that means except in zsh.

Answer 4

Simple example to change the prefix and the extension of all images in the current folder.

prefix=EG_
extension=.jpg
for i in $(ls); do mv $i "$prefix${i%.JPG}$extension";  done

If you want to check how it would effect your data before changing it replace the mv by echo

output for IMG_7993.JPG is EG_IMG_7993.jpg