Recently, while working with a bunch of files, I came to realize that I needed
to rename every single file. Not just that, I only needed to rename a small bit
of the filename. If I was working with a document, I wound have leveraged a
“search and replace” feature, but since this was files, I reached for my trusty
command-line.
The filenames in question don’t really matter, what happens is that I wanted to
take a file that was named like this:
some-great-filename-1.ext
And rename it to something like this:
some-amazing-filename-1.ext
There was no way in hell that I was going to do this manually in my file
explorer since it was over 100 files!
When I originally approached this, I ended up throwing a loop into the mix that
would generate a series of mv commands that used sed to do the string
replacement on the destination filename.
This worked great and made for a fun one-liner, but was also overkill once I had
discovered the rename command that I wasn’t aware existed initially.
The rename command is quite similar to mv in terms of usage and some of the
available options (like -i, --interactive which will prompt you when
overwriting files and keeps you safe).
Where rename is different than mv is that it takes an expression to match
against and a replacement to use before the filename / pattern that will be used
to match files.
A simple example would be renaming a bunch of files in a directory from one file
extension to another, something that mv can’t do with multiple files:
rename .ext1 .ext2 *.ext1
For my scenario with the aforementioned filenames, you can create some files to
follow along at home like this:
mkdir /tmp/joshtronic-rename
touch /tmp/joshtronic-rename/some-great-filename-{1..100}.ext
And then rename all of the files like so:
rename great amazing /tmp/joshtronic-rename/some-great-filename-*.ext
