witr

Why is this running?

1. Purpose

witr exists to answer a single question:

Why is this running?

When something is running on a system, whether it is a process, a service, or something bound to a port, there is always a cause. That cause is often indirect, non-obvious, or spread across multiple layers such as supervisors, containers, services, or shells.

Existing tools (ps, top, lsof, ss, systemctl, docker ps) expose state and metadata. They show what is running, but leave the user to infer why by manually correlating outputs across tools.

witr makes that causality explicit.

It explains where a running thing came from, how it was started, and what chain of systems is responsible for it existing right now, in a single, human-readable output.

2. Installation

witr is distributed as a single static binary for Linux, macOS, FreeBSD, and Windows.

witr is also independently packaged and maintained across multiple operating systems and ecosystems. An up-to-date overview of packaging status is available on Repology. Please note that community packages may lag GitHub releases due to independent review and validation.

[!TIP] If you use a package manager (Homebrew, Conda, Winget, etc.), we recommend installing via that for easier updates. Otherwise, the install script is the quickest way to get started.

2.1 Quick Install

Unix (Linux, macOS & FreeBSD)

curl -fsSL https://raw.githubusercontent.com/pranshuparmar/witr/main/install.sh | bash

Windows (PowerShell)

irm https://raw.githubusercontent.com/pranshuparmar/witr/main/install.ps1 | iex

2.2 Package Managers

Homebrew (macOS & Linux)

You can install witr using Homebrew on macOS or Linux:

brew install witr

Conda (macOS, Linux & Windows)

You can install witr using conda, mamba, or pixi on macOS, Linux, and Windows:

conda install -c conda-forge witr
# alternatively using mamba
mamba install -c conda-forge witr
# alternatively using pixi
pixi global install witr

Arch Linux (AUR)

On Arch Linux and derivatives, install from the AUR package:

yay -S witr-bin
# alternatively using paru
paru -S witr-bin
# or use your preferred AUR helper

Winget (Windows)

You can install witr via winget:

winget install -e --id PranshuParmar.witr

Chocolatey (Windows)

You can install witr using Chocolatey:

choco install witr

Scoop (Windows)

You can install witr using Scoop:

scoop install main/witr

FreeBSD Ports

You can install witr on FreeBSD from the FreshPorts port:

pkg install witr
# or
pkg install sysutils/witr

Or build from Ports:

cd /usr/ports/sysutils/witr/
make install clean

AOSC OS

You can install witr from the AOSC OS repository:

oma install witr

GNU Guix

You can install witr from the GNU Guix repository:

guix install witr

Uniget (Linux)

You can install witr using uniget:

uniget install witr

Brioche (Linux)

You can install witr using brioche:

brioche install -r witr

Aqua (macOS, Linux & Windows)

You can install witr using aqua:

# Add package
aqua g -i pranshuparmar/witr

# Install package
aqua i pranshuparmar/witr

2.3 Source & Manual Installation

go install github.com/pranshuparmar/witr/cmd/witr@latest

# 1. Determine OS and Architecture
OS=$(uname -s | tr '[:upper:]' '[:lower:]')
ARCH=$(uname -m)
[ "$ARCH" = "x86_64" ] && ARCH="amd64"
[ "$ARCH" = "aarch64" ] && ARCH="arm64"

# 2. Download the binary
curl -fsSL "https://github.com/pranshuparmar/witr/releases/latest/download/witr-${OS}-${ARCH}" -o witr

# 3. Verify checksum (Optional)
curl -fsSL "https://github.com/pranshuparmar/witr/releases/latest/download/SHA256SUMS" -o SHA256SUMS
grep "witr-${OS}-${ARCH}" SHA256SUMS | (sha256sum -c - 2>/dev/null || shasum -a 256 -c - 2>/dev/null)
rm SHA256SUMS

# 4. Rename and install
chmod +x witr
sudo mkdir -p /usr/local/bin
sudo mv witr /usr/local/bin/witr

# 5. Install man page (Optional)
sudo mkdir -p /usr/local/share/man/man1
sudo curl -fsSL https://github.com/pranshuparmar/witr/releases/latest/download/witr.1 -o /usr/local/share/man/man1/witr.1

# 1. Determine Architecture
if ($env:PROCESSOR_ARCHITECTURE -eq "AMD64") {
    $ZipName = "witr-windows-amd64.zip"
} elseif ($env:PROCESSOR_ARCHITECTURE -eq "ARM64") {
    $ZipName = "witr-windows-arm64.zip"
} else {
    Write-Error "Unsupported architecture: $($env:PROCESSOR_ARCHITECTURE)"
    exit 1
}

# 2. Download the zip
Invoke-WebRequest -Uri "https://github.com/pranshuparmar/witr/releases/latest/download/$ZipName" -OutFile "witr.zip"
# 3. Extract the binary
Expand-Archive -Path "witr.zip" -DestinationPath "." -Force

# 4. Verify checksum (Optional)
Invoke-WebRequest -Uri "https://github.com/pranshuparmar/witr/releases/latest/download/SHA256SUMS" -OutFile "SHA256SUMS"
$hash = Get-FileHash -Algorithm SHA256 .\witr.zip
$expected = Select-String -Path .\SHA256SUMS -Pattern $ZipName
if ($expected -and $hash.Hash.ToLower() -eq $expected.Line.Split(' ')[0]) { Write-Host "Checksum OK" } else { Write-Host "Checksum Mismatch" }

# 5. Install to local bin directory
$InstallDir = "$env:LocalAppData\witr\bin"
New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
Move-Item .\witr.exe $InstallDir\witr.exe -Force

# 6. Add to User Path (Persistent)
$UserPath = [Environment]::GetEnvironmentVariable("Path", "User")
if ($UserPath -notlike "*$InstallDir*") {
    [Environment]::SetEnvironmentVariable("Path", "$UserPath;$InstallDir", "User")
    $env:Path += ";$InstallDir"
    Write-Host "Added to Path. You may need to restart PowerShell."
}

# 7. Cleanup
Remove-Item witr.zip
Remove-Item SHA256SUMS

2.4 Run Without Installation

nix run github:pranshuparmar/witr -- --help

pixi exec witr --help

2.5 Other Operations

witr --version
man witr

sudo rm -f /usr/local/bin/witr
sudo rm -f /usr/local/share/man/man1/witr.1

Remove-Item -Recurse -Force "$env:LocalAppData\witr"

3. Flags & Options

      --env           show environment variables for the process
  -x, --exact         use exact name matching (no substring search)
  -f, --file string   file path to find process for
  -h, --help          help for witr
      --json          show result as JSON
      --no-color      disable colorized output
  -p, --pid string    pid to look up
  -o, --port string   port to look up
  -s, --short         show only ancestry
  -t, --tree          show only ancestry as a tree
      --verbose       show extended process information
  -v, --version       version for witr
      --warnings      show only warnings

A single positional argument (without flags) is treated as a process or service name. By default, name matching uses substring matching (fuzzy search). Use --exact to match only processes with the exact name.

4. Example Outputs

4.1 Name Based Query

witr node

Target      : node

Process     : node (pid 14233)
User        : pm2
Command     : node index.js
Started     : 2 days ago (Mon 2025-02-02 11:42:10 +05:30)
Restarts    : 1

Why It Exists :
  systemd (pid 1) → pm2 (pid 5034) → node (pid 14233)

Source      : pm2

Working Dir : /opt/apps/expense-manager
Git Repo    : expense-manager (main)
Listening   : 127.0.0.1:5001

4.2 Short Output

witr --port 5000 --short

systemd (pid 1) → PM2 v5.3.1: God (pid 1481580) → python (pid 1482060)

4.3 Tree Output

witr --pid 143895 --tree

systemd (pid 1)
  └─ init-systemd(Ub (pid 2)
    └─ SessionLeader (pid 143858)
      └─ Relay(143860) (pid 143859)
        └─ bash (pid 143860)
          └─ sh (pid 143886)
            └─ node (pid 143895)
              ├─ node (pid 143930)
              ├─ node (pid 144189)
              └─ node (pid 144234)

Note: Tree view includes child processes (up to 10) and highlights the target process.

4.4 Multiple Matches

witr ng

Multiple matching processes found:

[1] nginx (pid 2311)
    nginx -g daemon off;
[2] nginx (pid 24891)
    nginx -g daemon off;
[3] ngrok (pid 14233)
    ngrok http 5000

Re-run with:
  witr --pid <pid>

To avoid substring matching and only find processes with an exact name, use the --exact flag:

witr nginx -x

4.5 File Based Query

witr --file /var/lib/dpkg/lock

Explains the process holding a file open.

5. Platform Support

• Linux (x86_64, arm64) - Full feature support (/proc).
• macOS (x86_64, arm64) - Uses ps, lsof, sysctl, pgrep.
• Windows (x86_64, arm64) - Uses Get-CimInstance, tasklist, netstat.
• FreeBSD (x86_64, arm64) - Uses procstat, ps, lsof.

5.1 Feature Compatibility Matrix

Legend: ✅ Full support | ⚠️ Partial/limited support | ❌ Not available

5.2 Permissions Note

Linux/FreeBSD

witr inspects system directories which may require elevated permissions.

If you are not seeing the expected information, try running witr with sudo:

sudo witr [your arguments]

macOS

On macOS, witr uses ps, lsof, and launchctl to gather process information. Some operations may require elevated permissions:

sudo witr [your arguments]

Note: Due to macOS System Integrity Protection (SIP), some system process details may not be accessible even with sudo.

Windows

On Windows, witr uses Get-CimInstance, tasklist, and netstat. To see details for processes owned by other users or system services, you must run the terminal as Administrator.

# Run in Administrator PowerShell
.\witr.exe [your arguments]

6. Goals

Primary goals

• Explain why a process exists, not just that it exists
• Reduce time‑to‑understanding during debugging and outages
• Work with zero configuration
• Be safe, read‑only, and non‑destructive
• Prefer clarity over completeness

Non‑goals

• Not a monitoring tool
• Not a performance profiler
• Not a replacement for systemd/docker tooling
• Not a remediation or auto‑fix tool

7. Core Concept

witr treats everything as a process question.

Ports, services, containers, and commands all eventually map to PIDs. Once a PID is identified, witr builds a causal chain explaining why that PID exists.

At its core, witr answers:

1. What is running?
2. How did it start?
3. What is keeping it running?
4. What context does it belong to?

8. Output Behavior

8.1 Output Principles

• Single screen by default (best effort)
• Deterministic ordering
• Narrative-style explanation
• Best-effort detection with explicit uncertainty

8.2 Standard Output Sections

Target

What the user asked about.

Process

Executable, PID, user, command, start time and restart count.

Why It Exists

A causal ancestry chain showing how the process came to exist. This is the core value of witr.

Source

The primary system responsible for starting or supervising the process (best effort).

Examples:

• systemd unit (Linux)
• launchd service (macOS)
• docker container
• pm2
• cron
• interactive shell

Only one primary source is selected.

Context (best effort)

• Working directory
• Git repository name and branch
• Container name / image (docker, podman, kubernetes, colima, containerd)
• Public vs private bind

Warnings

Non‑blocking observations such as:

• Process is running as root
• Process is listening on a public interface (0.0.0.0 / ::)
• Restarted multiple times (warning only if above threshold)
• Process is using high memory (>1GB RSS)
• Process has been running for over 90 days

9. Success Criteria

witr is successful if:

• A user can answer "why is this running?" within seconds
• It reduces reliance on multiple tools
• Output is understandable under stress
• Users trust it during incidents