How to remove URI encoding from file names?

I realise this might be quite a simple question, but I’m still quite new to the command line and only have a grasp of basic commands.

I’ve downloaded some lecture presentations (~25 or so) from my University however on doing so they’ve been named things like…

L2%20Development%20of%20immune%20system.pptx
L4%20Molecular%20Recognition.pdf

As you can see they’ve downloaded with the URL encoding %20 instead of a space.

My question is how to batch rename all of these files so that the %20 is removed and replaced with a space instead?

Answers:

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Method 1

On Debian and derivatives (including Ubuntu), you could use rename, which applies a Perl expression to each file name.

rename 's/%20/ /g' L*
        |  |  | |   |
        |  |  | |   +--- Files to match
        |  |  | +------- globally
        |  |  +--------- with space
        |  +------------ %20
        +--------------- Substitute

I would consider using underscore instead of space – as it generally makes life easier in the cli world.

To generalise to all URI encoding:

rename 'use URI::Escape; $_ = uri_unescape $_' *%*

Method 2

You can use deurlname from renameutils.

$ ls
L4%20Molecular%20Recognition.pdf
$ deurlname L4%20Molecular%20Recognition.pdf
$ ls
L4 Molecular Recognition.pdf

I wrote a script that allows you to rename files in an editor.

You just pass the script a filename and it opens your editor with the filename
in it. Then you edit the filename, write, and close the editor.

$ ls
  L4%20Molecular%20Recognition.pdf
$ viname L4%20Molecular%20Recognition.pdf
  ======================
  L4%20Molecular%20Recognition.pdf█
  ======================

  ======================
  L4-Molecular-Recognition.pdf█
  ======================
  (pretend this is an editor)
$ ls
  L4-Molecular-Recognition.pdf

I also wrote a script
that automatically renames files to conform to my preferred naming scheme. When
I download files, the first thing I do is call this script on them.

$ ls
  L4%20Molecular%20Recognition.pdf
$ nf L4%20Molecular%20Recognition.pdf
  'L4%20Molecular%20Recognition.pdf' renamed to 'l4-molecular-recognition.pdf'
$ ls
  L4-molecular-recognition.pdf

Be careful with that script. It can do some rather dramatic renames. Use its
dry run (nf -n) option before renaming any files.

Method 3

You could use convmv in the directory where you have the files:
To test what the output would be:

convmv --unescape *%20*

To actually rename the files add --notest:

convmv --unescape --notest *%20*

Method 4

Another alternative that doesn’t rely on external tools outside of bash:

for old in *; do
    new="${old//+/ }"
    printf -v new '%b' "${new//%/x}"
    mv -- "$old" "$new"
done

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0