Winix WhoHolds is a command-line tool designed to identify which processes hold file locks or bind network ports on your system. This utility simplifies troubleshooting by providing insights into resource usage that can otherwise be difficult to track.
Key Features:
File Lock Detection: Quickly find out which processes are holding exclusive locks on specific files, helping you resolve access conflicts.
Port Binding Analysis: Discover which applications or services are listening on network ports, aiding in diagnosing connectivity issues and port conflicts.
Audience & Benefit:
Ideal for developers, system administrators, and IT professionals who need to troubleshoot resource contention. Winix WhoHolds provides a straightforward way to identify and resolve issues related to file access and network port usage, streamlining system management and debugging processes.
This tool is part of the Winix suite, a collection of cross-platform CLI utilities designed to bridge gaps between Windows and Unix-like systems. It can be installed via winget for easy integration into your workflow.
README
Winix
Small, native, cross-platform CLI tools — the same behaviour everywhere.
Winix is a suite of focused command-line tools compiled to native binaries via .NET AOT. One .exe per tool: no runtime to install, no POSIX emulation layer, no shell dependency. Each tool works identically in cmd.exe, PowerShell, bash, zsh, CI agents, File Explorer "Open with", and scheduled tasks, on Windows, Linux, and macOS — same flags, same output, same exit codes. Scripts and muscle memory transfer across platforms without adaptation.
On Windows, many of these tools simply don't exist natively — there's no built-in find, xargs, watch, man, less, or netcat. On Unix, Winix papers over BSD-vs-GNU flag differences, adds structured output to tools that were never designed to be parsed, and provides the same interface that's available on Windows. Output is colourful and readable for humans in the terminal by default; every tool also has a --json mode for scripts and agents.
Suite installer — installs and updates all tools via native package managers
Tools marked fresh (mksecret, trash, hcat, mkauth, demux) are newer additions that have not yet shipped in a stable release — their interfaces may still change. All other tools are core (stable). See docs/STABILITY.md for the full policy.
Why each tool, on each platform
The biggest value is on Windows, where many of these tools simply don't exist. On Linux and macOS the tools still earn their keep by combining multiple utilities, improving defaults, or providing a consistent interface across platforms. Even where a native equivalent exists, there's value in a single set of tools that behaves identically everywhere — scripts, CI pipelines, and muscle memory transfer across platforms without adaptation.
The table below highlights a representative selection; the Tools table above lists the full suite, and each tool's README has its own "what it replaces, on each OS" rationale.
Tool
Windows
Linux / macOS
timeit
Nothing built-in. Measure-Command exists but doesn't show memory, doesn't pass exit codes, can't be piped.
Improves on time with peak memory, machine-readable JSON, and proper exit-code passthrough.
squeeze
No native CLI for compression. Users install 3+ separate tools or reach for 7-Zip.
One tool instead of separate gzip, brotli, zstd CLIs. Auto-detects format on decompression.
peep
No watch. No entr. PowerShell loops are verbose and don't handle file-watching.
Combines watch (interval) + entr (file-change trigger) in one binary with a TUI.
wargs
No xargs. ForEach-Object is PowerShell-only and doesn't handle parallel execution or line-delimited input well.
Sane defaults over xargs: line-delimited, no -0 needed, correct quoting on all platforms.
files
No find. Get-ChildItem exists but is slow, verbose, and PowerShell-only.
Cleaner than find, with glob patterns, gitignore support, text/binary detection, and JSON output.
treex
Built-in tree is bare-bones (no colour, no sizes, no filtering).
Adds colour, size rollups, gitignore, clickable hyperlinks, and filtering over standard tree.
man
No man at all.
Alternative renderer with colour and hyperlinks. Renders groff natively — no groff install needed. Bundled pager.
less
No pager. more exists but can't scroll back, search, or handle ANSI colour.
Better defaults than system less: ANSI colour on by default, mouse scroll, follow mode.
whoholds
No built-in file-lock query. handle.exe (Sysinternals) requires a separate download + admin rights.
Wraps lsof with cleaner output, structured JSON, and a unified syntax for both files and ports.
schedule
schtasks.exe exists but is notoriously hard to script. No cron syntax.
Unified interface over crontab with the same flags and output format as Windows.
nc
No netcat. Test-NetConnection is verbose and limited.
Consistent behaviour across BSD/GNU/ncat forks. Adds TLS client support and port-range checking.
winix
Suite installer via Scoop or winget.
Suite installer via brew or dotnet tool.
Prior art — Cygwin, WSL, Git Bash
Unix tools have been available on Windows for decades via Cygwin, MSYS2 / Git Bash, and WSL. These are excellent at what they do — they bring a full POSIX environment (bash, coreutils, rsync, ssh, a few thousand packages) to Windows so real Linux binaries can run there.
Winix takes a different approach and is complementary rather than competing:
No emulation layer. Tools are native .exe files, not POSIX binaries calling cygwin1.dll. Paths are native (C:\foo, not /cygdrive/c/foo). No fork-emulation overhead, no path translation surprises.
Redistributable on their own. Copy a single .exe to a machine and it works. No Cygwin base install, no cygwin1.dll alongside it, no $PATH gymnastics.
First-class outside bash. Works from cmd.exe, PowerShell, File Explorer "Open with", Windows Task Scheduler actions, IIS hooks, SSIS packages — not just inside a mintty + bash session.
Package-manager installable per tool.scoop install winix/timeit, winget install Winix.TimeIt, dotnet tool install -g Winix.TimeIt — seconds on a CI runner, no base environment required.
Cross-platform source, not a Windows port. Linux and macOS builds aren't afterthoughts — the same source compiles to native binaries on every platform, with identical behaviour and flags everywhere.
If you want the entire GNU/Unix userland on Windows and you're happy working inside a bash shell, Cygwin or WSL is the right tool — and Winix runs fine alongside either of them. If you want a smaller, focused set of modern CLI utilities that integrate with whatever environment you're already in, that's what Winix is for.
More tools are being submitted to winget over time (submissions are human-moderated, so they land in batches). For tools not yet on winget, use Scoop, the .NET tool, or GitHub Releases below — all of which cover the full suite.
.NET Tool (cross-platform)
Every tool publishes to NuGet as a .NET global tool under the ID Winix.. Install any of them with dotnet tool install -g:
The full set of package IDs: Winix.TimeIt, Winix.Squeeze, Winix.Peep, Winix.Wargs, Winix.Files, Winix.Less, Winix.Man, Winix.TreeX, Winix.When, Winix.WhoHolds, Winix.Schedule, Winix.NetCat, Winix.Retry, Winix.Clip, Winix.Ids, Winix.MkSecret, Winix.Digest, Winix.EnvVault, Winix.Notify, Winix.Protect, Winix.Unprotect, Winix.Qr, Winix.Url, Winix.Trash, Winix.HCat, Winix.Demux, Winix.MkAuth, Winix.Winix.
Direct Download
Download native binaries from GitHub Releases.
Available for Windows (x64), Linux (x64), and macOS (x64, ARM64). Windows binaries are Authenticode-signed.
Quick Start
# Time a build
timeit dotnet build
# Watch tests, re-run on file changes
peep -w "src/**/*.cs" dotnet test
# Compress with zstd
squeeze --zstd largefile.bin
# Find files and batch-process them
files src --ext cs | wargs dotnet format
# Browse a directory tree with sizes
treex --size --gitignore --no-hidden
# Read a man page on any platform
man timeit
# Find what's locking a file
whoholds myapp.dll
# Quick port check
nc -z db.internal 5432
# Schedule a recurring job (cross-platform cron)
schedule add "0 9 * * 1-5" -- backup.sh /data
# JSON output for CI
timeit --json dotnet test
# AI agent metadata
files --describe
For AI agents
Winix tools are designed to be invoked by scripts and agents, not just humans:
--describe on every tool returns structured JSON metadata — flags, types, defaults, examples, composability hints, exit codes, and the --json output schema.
--json on every tool produces machine-parseable output with standard, documented fields.
Consistent exit codes across the suite (0 = success, 125 = usage error).
AGENTS.md at the repo root sets out when reaching for a Winix tool is actually the right call versus the POSIX or Windows default — Winix isn't a blanket replacement, and the file is explicit about that.
llms.txt plus per-tool agent guides in docs/ai/ give agents a single entry point to discover the suite, with a one-line summary per tool and full agent-targeted documentation per tool.
