zap

Too many dev servers running and ports colliding? Can't remember the netstat incantation to figure out what's hogging port 3000?

zap gives you a live TUI to find processes by port and kill them — with proper handling for containers (Podman/Docker) and systemd services. The list auto-refreshes every 2 seconds so you can watch a service come up, confirm a kill took effect, or spot new port conflicts without pressing a key.

Install

go install github.com/dnlvgl/zap/cmd/zap@latest

Or build from source:

go build -o zap ./cmd/zap/

Usage

# Interactive TUI showing all listening ports
zap

# Target a specific port
zap :3000

# Port range
zap :8080-8090

# Specific interface
zap localhost:5432

# Force kill (SIGKILL)
zap :3000 --force

# Dry run (non-interactive, shows what would be killed)
zap :3000 --dry-run

Kill strategies

zap automatically picks the best way to stop a process:

1. Container — podman stop / docker stop for containerized processes
2. Systemd — systemctl stop for systemd-managed services
3. Signal — SIGTERM (or SIGKILL with --force) for bare processes

Flags

Flag	Short	Description
--force	-f	Use SIGKILL / container kill instead of graceful stop
--dry-run	-n	Show what would be killed (non-interactive)
--version	-v	Print version
--help	-h	Show help

Releasing a new version

Pushing a v* tag triggers the GitHub Actions release workflow, which uses GoReleaser to build and publish binaries.

git tag v0.2.0
git push origin v0.2.0