Renaming files is something that occurs frequently, and in Linux on terminal, there are many ways to rename files. Let's look at some of the main ways you can rename your files on Linux and other Unix based systems like MacOS.

Linux Commands

If you're brand new to Linux commands, read my full guide on Linux commands them here.

Renaming files with the mv Command

The mv command moves a file to another place. It can also be used to move a file to the same location, and simply change it's name. For example, if you wanted to rename a file called file-1.txt to file-2.txt, you would first cd into that directory, and run the following:

mv file-1.txt file-2.txt

This technically "moves" the file, but in reality the end result is that the file is renamed and in the same location.

Renaming multiple files

If you want to rename more than one file at once, we can't just use the mv command. For that, we need to loop through each file we want to rename. We can use this in conjunction with the find command to find all the files that fit our criteria easily. For example, the below will find all .txt, .csv and .html files, and turn them into .js files:

for f in $(find . -name '*.txt' -or -name '*.csv' -or -name '*.html'); do 
    mv $f ${f%.*}.js
done

Let's look at how this works in a little more detail:

• We run a for loop, for f in $(). This will find all files, where it matches what is inside $(). In this example, it finds anything with the file type .txt, .csv, or .html. You can learn more about find here.
• For each of the matching files, we run the mv command. We run mv $f ${f%.*}.js.
• $f is the current matching file we are looping through.
• ${f%.*}.html is saying rename any file with any extenstion ({f%.*} could be {f%.html}, {f%.csv}, etc), and change its name to the file name with our new extension, .js.

After that, you'll have successfully moved all files.