Bash Rename File Extensions

From Luke Jackson

Contents 1 Summary 2 Supported Operating Systems 3 Requirements 4 Syntax

Summary

This is a simple function to quickly rename many files using Bash. It can be very useful for renaming pictures, mp3s, and movies.

Supported Operating Systems

• Mac OS X and Terminal
• Unix
• Linux

Requirements

• Bash

Syntax

Below is a simple example for renaming uppercase jpg files to lowercase:

for i in *.JPG; do mv $i ${i%%.JPG}.jpg; done

for f in *.jpg; do mv "$f" "${f%.jpg}"; done

If you would like to use this function for other types of files here is a basic template:

for i in *.<EXISTING_EXT>; do mv $i ${i%%.<EXISTING_EXT>}.<RESULTING_EXT>; done

Another examples

for i in *.JPG; do j=`echo $i | cut -d . -f 1`; j=$j"_from_mark.jpg"; echo $j; mv $i $j; done;

for i in *.py; do cp "$i" "${i%-*}.py"; done

for i in *.py; do mv "$i" "${i%.py}-json.py"; done

String Operations

for i in *; do mv $i ${i#1440.jpg.*}.jpg; done

printf "%s\n" img{00{1..9},0{10..99},{100..999}}.png

Basic Example (Files without File Extensions)

for f in *; do mv "$f" "$f.jpg"; done