One of the most annoying problems when copying code or text from the web is the automatic use of smart quotes (also called curly quotes or typographic quotes).

Instead of getting:

"hello"

you end up with:

“hello”

For regular writing this is fine, but for developers it can become a nightmare because many programming languages expect plain ASCII quotes.

Why This Happens

Many modern websites, editors, and rich text systems automatically replace straight quotes with typographic ones.

Examples:

This commonly happens when copying from:

• Blogs
• Documentation sites
• AI-generated content
• PDFs
• Microsoft Word
• Google Docs
• CMS editors
• Messaging apps

Even if smart quotes are disabled on your own system, copied web content may still contain them.

Why Developers Hate This

These characters can silently break:

• PHP
• Shell scripts
• SQL
• JSON
• YAML
• .env files
• nginx configs
• JavaScript

Example:

echo “Hello”;

This looks valid at first glance, but PHP will throw an error because “ and ” are not valid string delimiters.

The worst part is that some fonts make them almost indistinguishable from normal quotes.

The Goal

Automatically sanitize clipboard contents system-wide on Kubuntu so that:

“ ”
‘ ’

becomes:

" "
' '

without manually running commands every time.

The Solution

A small background clipboard watcher script.

The script continuously watches the clipboard and automatically replaces smart quotes with plain ASCII quotes whenever new text is copied.

This works especially well on Kubuntu/X11.

Install Required Tools

Install xsel:

sudo apt install xsel

Create the Clipboard Cleaner Script

Create a scripts directory if needed:

mkdir -p ~/Scripts

Create the script:

nano ~/Scripts/clipboard-cleaner.sh

Paste the following:

#!/bin/bash

last=""

while true; do
    current=$(xsel --clipboard --output 2>/dev/null)

    if [ -n "$current" ] && [ "$current" != "$last" ]; then

        cleaned=$(printf '%s' "$current" | \
            sed \
                -e 's/[“”]/"/g' \
                -e "s/[‘’]/'/g")

        if [ "$cleaned" != "$current" ]; then
            printf '%s' "$cleaned" | xsel --clipboard --input
        fi

        last="$cleaned"
    fi

    sleep 0.2
done

Save and exit.

Make the Script Executable

chmod +x ~/Scripts/clipboard-cleaner.sh

Test It

Run the script:

~/Scripts/clipboard-cleaner.sh

Now copy:

“hello” and ‘test’

Paste somewhere.

You should get:

"hello" and 'test'

The Better Approach: Run It Automatically with systemd

Instead of manually launching the script every time, create a user-level systemd service.

This allows the clipboard cleaner to:

• Start automatically at login
• Run silently in the background
• Restart automatically if it crashes
• Behave like a native desktop service

Create the systemd User Service

Create the service directory:

mkdir -p ~/.config/systemd/user

Create the service file:

nano ~/.config/systemd/user/clipboard-cleaner.service

Paste:

[Unit]
Description=Clipboard Smart Quote Cleaner

[Service]
ExecStart=/home/miguelgarcia/Scripts/clipboard-cleaner.sh
Restart=always
RestartSec=1

[Install]
WantedBy=default.target

Replace /home/miguelgarcia/ with your own username/path if needed.

Enable the Service

Reload systemd:

systemctl --user daemon-reload

Enable and start the service:

systemctl --user enable --now clipboard-cleaner.service

Useful Commands

Check service status:

systemctl --user status clipboard-cleaner.service

Stop the service:

systemctl --user stop clipboard-cleaner.service

Start it again:

systemctl --user start clipboard-cleaner.service

Disable automatic startup:

systemctl --user disable clipboard-cleaner.service

Why This Approach Is Nice

This solution works system-wide across:

• Browsers
• PDFs
• AI outputs
• Messaging apps
• Documentation websites
• Rich text editors

without needing to manually clean pasted text.

It becomes especially useful for developers working with:

• PHP
• Symfony
• Bash
• SQL
• JSON
• YAML
• nginx
• .env files

Future Improvements

The script can easily be expanded to normalize additional problematic Unicode characters.

Examples:

Example additions:

-e 's/—/--/g' \
-e 's/…/.../g'

Final Thoughts

Modern websites increasingly inject invisible Unicode formatting into copied text.

For developers, this can lead to:

• Broken scripts
• Invalid configuration files
• Hard-to-debug syntax errors
• Random parsing failures

This clipboard cleaner creates a safer development workflow by automatically normalizing copied text into clean ASCII characters before pasting.