Dev Tip: Automatically Copy Console Output to Clipboard¶

Category: Linux / Shell Productivity
Platform: Linux (zsh + Konsole/KDE)

The Problem¶

When working with AI assistants, you often need to copy terminal output and paste it into the chat. This usually means:

Run command
Select output with mouse
Copy
Switch to browser
Paste

That’s too many steps.

The Solution: Auto-capture via `preexec` / `precmd`¶

Add this to your ~/.zshrc:

# === AUTO-OUTPUT LOGGER ===
# Automatically saves console output to ~/t.txt and copies to clipboard.
# Toggle: set AUTO_CLIPBOARD=true/false
AUTO_CLIPBOARD=true

# Redirect stdout+stderr to ~/t.txt before each command
preexec() {
    case "$1" in
        sudo*|su*) return ;;
        *) exec > >(tee ~/t.txt) 2>&1 ;;
    esac
}


precmd() {
    exec >/dev/tty 2>&1
    if [ "$AUTO_CLIPBOARD" = "true" ] && [ -s ~/t.txt ]; then
        cleaned=$(cat ~/t.txt \
            | sed 's/\][0-9]*;[^]]*\][0-9]*;//g; s/^[0-9]*;//g' \
            | sed "s|$HOME|~|g" \
            | sed 's/[^[:print:]]//g' \
            | grep -v '^$')
        if [ -n "$cleaned" ]; then
            echo "$cleaned" | xclip -selection clipboard
            echo "[📋 In Zwischenablage kopiert]"
        fi
    fi
}

Then reload:

source ~/.zshrc

Result¶

After every command, the output is automatically in your clipboard — ready to paste into your AI chat with Ctrl+V.

The output is also always saved in ~/t.txt for reference.

How it works¶

Part	What it does
`preexec()`	Runs before each command, redirects output to `~/t.txt`
`precmd()`	Runs after each command, restores stdout and copies to clipboard
`tee ~/t.txt`	Saves output to file while still showing it in terminal
`sed '...'`	Strips KDE Konsole title escape sequences (`]2;...` `]1;`)
`xclip`	Copies cleaned output to clipboard

Requirements¶

# Install xclip if not present
sudo pacman -S xclip       # Manjaro/Arch
sudo apt install xclip     # Ubuntu/Debian

⚠️ What NOT to do¶

Do not use fc -ln -1 | bash to re-execute the last command:

# ❌ DANGEROUS - do not use!
precmd() {
    output=$(fc -ln -1 | bash 2>&1)  # Re-executes last command!
    echo "$output" | xclip -selection clipboard
}

This re-executes every command after it finishes, which can cause destructive side effects — for example overwriting files, re-running git commit, re-running sed -i, etc.

The preexec/precmd approach above captures output during execution — safe and reliable.