Bash script to batch rename files

This is my homebrew bash script for batch renaming files extensions (my music library needs organizing):

#!/bin/bash

# rext.sh
# Syntax: rext.sh EXT1 EXT2
# Batch rename any file in current directory with extension of EXT1 to EXT2

EXT1=$1
EXT2=$2

for f in *.$EXT1
do
  fname=${f%.*}
  newfname="$fname.$EXT2"
  mv -v -i "$f" "$newfname"
done

It works beautifully with my music files, but is this code sufficient or can I still improve on it? Also I've seen examples using rename instead of mv, so is there any advantage in using rename?

A tiny mistake is not quoting $EXT1 in for f in *.$EXT1.
If it contains a space, the script won't work as expected.
I agree it's an unrealistic corner case,
but it's easy enough to protect against with proper quoting: for f in *."$EXT1".

The rename Perl script is famous for this purpose.
Since you asked about its advantages:

• Stood the test of time

• You don't have to write it

• It has more features (full regex support)

The equivalent usage to simulate the behavior of your script would be:

rename -v 's/EXT1$/EXT2/' *.EXT1

A feature I like is the -n flag for dry run, to verify the renames that would be performed before actually performing them.

StackExchange Code Review Q#163186, answer score: 6