Mine is called “porthole”

https://github.com/clutchski/dotfiles/blob/main/home/bin/por...

I am absolutely installing this and starting to use it daily!

For the even less patient there's also this (not mine): https://github.com/jkfran/killport

i have this in my .zshrc which provides same functionality:

  lk() {
    if [ $# -eq 0 ]; then
        local output=$(sudo lsof -iTCP -sTCP:LISTEN -n -P)
    elif [ $# -eq 1 ]; then
        local output=$(sudo lsof -iTCP -sTCP:LISTEN -n -P | grep -i --color=always $1)
    else
        echo "find and kill processes listening on ports. Usage: lk [pattern]"
        return 1
    fi

    if [ -z "$output" ]; then
        echo "No listening processes found."
        return 0
    fi

    # Show header + results
    echo "$(sudo lsof -iTCP -sTCP:LISTEN -n -P | head -1)"
    echo "$output"
    echo ""

    # Extract unique PIDs (skip the header row if no grep was applied)
    local pids=($(echo "$output" | awk '{print $2}' | grep -E '^[0-9]+$' | sort -u))

    if [ ${#pids[@]} -eq 0 ]; then
        echo "No PIDs found."
        return 0
    fi

    echo "PIDs to kill: ${pids[*]}"
    echo -n "Kill these ${#pids[@]} process(es)? [y/N] "
    read -r confirm

    if [[ "$confirm" =~ ^[Yy]$ ]]; then
        for pid in "${pids[@]}"; do
            echo "Killing PID $pid..."
            sudo kill -9 $pid
        done
        echo "Done."
    else
        echo "Aborted."
    fi
  }

Would be nice to have a flag to customize the URL displayed for Docker containers. I connect to my host via Tailscale, but I can’t open links with localhost. It would be helpful to have a parameter that allows us to choose a network device or specify an IP address to display.

    3000    wud (getwud/wud:latest)                            wud          getwud/wud:latest                       3000    http://localhost:3000
    3001    dockhand (fnsys/dockhand:latest)                   dockhand     fnsys/dockhand:latest                   3000    http://localhost:3001

Sonar as in SonarQube? That's an interesting choice for a name :)

I always have a bunch of local projects running, particularly during the weekend where I'm rarely working on one thing at a time. A big pain of mine was constantly running into port: Redis from one project blocking another, orphaned dev servers from old worktrees, Docker containers I forgot about. The usual fix is lsof -iTCP | grep ..., then figuring out what the PID actually is, then killing it. But I always forget the command, and it doesn’t really include all the information that I like.

So I built this lightweight CLI. Single binary, no dependencies. It shows everything listening on localhost with process names, Docker container info, clickable URLs etc.

Sure there are workarounds, but none that satisfied my need for a short, easily rememberable command. Also nothing really has the same satisfaction as running sonar kill 3000 — it just feels nice. I’ve already been approached by a few agent orchestration tools that have been struggling with the same thing. It's really useful when you have multiple agents running, but it's not built for just that use case, I have also find it handy when killing off all containers after a failed cleanup and so on. Also know that MCPs are dead and CLIs are the new thing in agentic coding, this might be a useful tool for Claude, particularly when a compose process exits before all containers are stopped.

Open for contributions, ideas and feedback.

love this, happens too often

love this, i get tired of spamming lsof -i tcp:xxxx