Show HN: Witr – Explain why a process is running on your Linux system

352 points by pranshuparmar 21 hours ago

Hi HN,

I built a small Linux CLI tool called witr (Why Is This Running?).

The idea came from a situation most of us have hit: you log into a machine, see a process or port running, and immediately wonder why it exists, who started it, and what is keeping it alive right now.

witr traces a process, service, or port back to its origin and responsibility chain and explains it in a way that’s quick to read, especially when you’re debugging under pressure.

This is v0.1.0. It’s intentionally small and focused. Feedback, criticism, and edge cases are very welcome.

Repo: https://github.com/pranshuparmar/witr

mh- - 14 hours ago

This is great. Small, trivial suggestion: the gif that loops in the README should pause on the screen w/ the output for a few seconds longer - it disappears (restarts) too quickly to take in all of the output.

godelski - 10 hours ago
```
  > the gif that loops in the README should pause on the screen
```
Honestly, I think a screenshot is better than a gif. That last frame says everything you need.
pranshuparmar - an hour ago

Thanks everyone for the feedback on the GIF! I though it looked good but when I went back to see it from a user's POV, it was really miserable, haha. I've already switched it to a static image, appreaciate everyone's input and suggestions.
Neywiny - 14 hours ago

I would also argue it shouldn't be a gif. It's nice that it shows the command is fast I guess but it's one command that's still visible in the final frame. Not as bandwidth efficient and agreed I can't read it all in time
thaumasiotes - 2 hours ago

You can make that problem irrelevant with the much, much simpler solution of not animating it at all. Stay paused on the output 100% of the time!
The gif is adding no value. I already know what typing text into a terminal looks like.
stavros - 14 hours ago

https://github.com/charmbracelet/vhs is a really good utility for automatically making these gifs.
- sestep - 13 hours ago
  
  I'm a big fan of svg-term myself: https://github.com/marionebl/svg-term-cli
  - stavros - 13 hours ago
    
    Hm, very interesting! This only converts asciinema recordings, though, right? It doesn't automatically record anything?
    
    sestep - 13 hours ago
    
    If you have asciinema already installed then you can invoke it through svg-term like this!
    svg-term --command 'cowsay hey there'
    But that has the aforementioned issues about not pausing enough, so I usually just record with asciinema first and then invoke svg-term.
rzzzt - 12 hours ago

Also the pause button seems to take the GIF back to its first frame, then resume from where I paused... either that or I need a good sleep.

pranshuparmar - 21 hours ago

A quick note on scope: this is not meant to replace existing monitoring or observability tools. It’s designed for those moments when you SSH into a box and need to quickly understand “why is this running” without digging through configs, cron jobs, or service trees manually.

Happy to answer questions or adjust direction based on feedback.

dcminter - 17 hours ago

This is very clever. I've often needed to figure out what some running process was actually for (e.g. because it just started consuming a lot of some limited resource) but it never occurred to me that one could have a tool to answer that question. Well done.
---
Edit: Ah, ok, I slightly misunderstood - skimmed the README too quickly. I thought it was also explaining what the process did :D Still a clever tool, but thought it went a step further.
Perhaps you should add that though - combine Man page output with a database of known processes that run on various Linux systems and a mechanism for contributing PRs to extend that database...? Unlesss it's just me that often wants to know "what the fsck does /tmp/hax0r/deeploysketchyd actually do?" :P
- filterfish - 8 hours ago
  
  Looking up the binary in the package management system would also provide another source of useful information. Of course this would dramatically increase the complexity but would, I think, be useful.
  If you could look it up using APT/dpkg first, that would be lovely :-)
  - ajb - 3 hours ago
    
    If you have its path, dpkg already has an option to do that: "dpkg -S". Although some extra logic is needed for symlinks.
- pranshuparmar - an hour ago
  
  Thanks, glad you liked it! As @darrenf mentioned, `whatis` can help with that use case. For now, I’m keeping `witr` focused on explaining PIDs.
- darrenf - 4 hours ago
  
  Is that not `whatis`?
  https://www.man7.org/linux/man-pages/man1/whatis.1.html

saidnooneever - an hour ago

seems handy but mostly the ppid is outputted as the reason for starting. its 'who dun it', not really _why_ it was started. (service file, autorun, execve etc.)

i see you support multiple output format including json thats nice. id recommend to assume automation (ssh script/commands) and make the default output really easily greppable , or json (jq) since itll be more appealing to parse (shouldnt reduce readability, for the default output it looks like just removing some linebreaks to make it parse more consistently. (maybe the lines are wrapped tho? unclear from the img)

pranshuparmar - 17 minutes ago

Thanks for the feedback! I’ll look into showing who and why in a more distinct way. The default output is human-first, hence some extra line breaks, but the JSON flag is already there for automation. We can also see if it can be made more easily greppable.

vzaliva - 12 hours ago

Sounds like something I could use, but installing a binary via `curl` doesn't sit right with me. Next problem you have is "explain how this thing was installed on my system" followed "is it up to date (including security patches).

I hope they have deb package or snap some day.

pranshuparmar - an hour ago

I understand that installing via `curl` isn’t for everyone, but since this is the first release, I intentionally kept it simple. Now that the tool is gaining some traction, I can definitely plan proper packages for future releases. Thanks for your inputs.
fouc - 11 hours ago

new utility command coming soon! wdtci - "what does this curl install?"
klooney - 10 hours ago

`systemctl status $pid` will get you a lot

zenoprax - 9 hours ago

> witr is successful if users trust it during incidents.

> This project was developed with assistance from AI/LLMs [...] supervised by a human who occasionally knew what he was doing.

This seems contradictory to me.

zephyreon - 8 hours ago

The last bit
> supervised by a human who occasionally knew what he was doing.
seems in jest but I could be wrong. If omitted or flagged as actual sarcasm I would feel a lot better about the project overall. As long as you’re auditing the LLM’s outputs and doing a decent code review I think it’s reasonable to trust this tool during incidents.
I’ll admit I did go straight to the end of the readme to look for this exact statement. I appreciate they chose to disclose.
- pranshuparmar - 31 minutes ago
  
  Thank you, yes I added it in jest and still keeping it for sometime. It was always meant to be removed in future.
- otabdeveloper4 - 5 hours ago
  
  If you're capable of auditing the LLM’s outputs and doing a decent code review then you don't need an LLM.
  - Retr0id - 5 hours ago
    
    Nobody who was writing code before LLMs existed "needs" an LLM, but they can still be handy. Procfs parsing trivialities are the kind of thing LLMs are good at, although apparently it still takes a human to say "why not using an existing library that solves this, like https://pkg.go.dev/github.com/prometheus/procfs"
    
    otabdeveloper4 - 5 hours ago
    
    > Procfs parsing trivialities are the kind of thing LLMs are good at
    Have you tried it? Procfs trivialities is exactly the kind of thing where an LLM will hallucinate something plausible-looking.
    Fixing LLM hallucinations takes more work and time than just reading manpages and writing code yourself.
    
    Retr0id - 4 hours ago
    
    Claude code can read manpages too
    
    otabdeveloper4 - 7 minutes ago
    
    If I'd ever feel the urge to misengineer a rube goldberg contraption to manage my vibe coder LLM output I'll get back to you.
    But at the moment I feel like all that sounds suspiciously like actual work.
    
    delusional - 3 hours ago
    
    It cant "read" anything. It can include the man page in the prompt, but it can never "read" it.
    
    Retr0id - 2 hours ago
    
    If the output is working code I don't really care whether it's reading, "reading", or """reading"""
  - littlestymaar - 4 hours ago
    
    Neither do you need and IDE, syntax highlighting or third party libraries, yet you use all of them.
    There's nothing wrong for a software engineer about using LLMs as an additional tool in his toolbox. The problem arises when people stops doing software engineering because they believe the LLM is doing the engineering for them.
    
    otabdeveloper4 - 5 minutes ago
    
    I don't use IDEs that require more time and effort investment than they save.
    You mileage may vary, though. Lots of software engineers love those time and effort tarpits.
pranshuparmar - an hour ago

Fair enough! That line was meant tongue‑in‑cheek, and to be transparent about LLM usage. Rest assured, they were assistants, not authorities.
solarkraft - 7 hours ago

No to me. It just has to demonstrate to work well, which is plenty possible with a developer focused on outcome rather than process (though hopefully they cared a bit about process/architecture too).
Retr0id - 5 hours ago

Regardless of code correctness, it's easy enough for malware to spoof process relationships.
guywithahat - 7 hours ago

I agree, the LLM probably has a much better idea of what's happening than any human

be_erik - 14 hours ago

If you're looking to build and install this from source, here's the incantation:

CGO_ENABLED=0 go build -ldflags "-X main.version=dev -X main.commit=$(git rev-parse --short HEAD) -X 'main.buildDate=$(date +%Y-%m-%d)'" -o witr ./cmd/witr

Call me old-fashioned, but if there's an install.sh, I would hope it would prefer the local src over binaries.

Very cool utility! Simple tools like these keep me glued to the terminal. Thank you!

pranshuparmar - 42 minutes ago

Thanks! Glad you like it Thanks to @sestep, Nix support is already added, so no need to worry about binaries.
sestep - 13 hours ago

Alternatively you can use Nix! :P https://github.com/pranshuparmar/witr/pull/5

cedsam - 4 hours ago

This is amazing and really useful to me. Great job.

However, I can’t use it in a production business environment for the same reasons other users mentioned earlier. A Debian or RPM package would be fantastic.

pranshuparmar - an hour ago

Thank you, glad you liked it. Since this is the first release, I intentionally kept it simple. Now that the tool is gaining some traction, I can definitely plan proper packages for future releases. Thanks for your inputs.

DougN7 - 14 hours ago

What does this means for context: “Git repository name and branch” Does this mean it detects if something is running from within a git repository folder? Couldn’t find the code that checked this.

jackwilsdon - 14 hours ago

It appears to walk up from the process's working directory searching for a .git directory: https://github.com/pranshuparmar/witr/blob/1e47bdb8fde179b17...
- pranshuparmar - 40 minutes ago
  
  Yes, that's correct! It walks up from the process’s working directory looking for a `.git` folder to detect the repo and branch. Thanks.

epiccoleman - 7 hours ago

Cool idea. Reminds me of my alias "whodis" which just lsofs a port to find out the pid who's got it open, but way more functional.

pranshuparmar - 38 minutes ago

Thanks! Glad you like it Trying to make this a swiss army knife for PID information.

TheCraiggers - 16 hours ago

This is amazing. Thank you for sharing this.

Do you have any qualms about me making an entry in the AUR for this?

pranshuparmar - 36 minutes ago

Thanks! Really appreciate it. No qualms at all — an AUR entry would be awesome!
giancarlostoro - 15 hours ago

Im not the author but I would love for an AUR made for this ;)
My favorite thing about arch is how insanely quickly AURs pop up for interesting tools.
- - 36 minutes ago
  
  [deleted]

jsomedon - 2 hours ago

Brilliant stuff! Any plan to support macos?

pranshuparmar - 35 minutes ago

Thank you, yes coming soon - https://github.com/pranshuparmar/witr/pull/9

techsystems - 15 hours ago

I'm really loving this!

'Responsibility chain' will become a trendy phrase.

pranshuparmar - 34 minutes ago

Haha, glad you like it! Maybe "responsibility chain" will catch on.

4ggr0 - 17 hours ago

i definitely see the use for it, lots of moments where i wonder how or why something was started.

pranshuparmar - 8 minutes ago

Thank you, please feel free to share any feedback/ideas.

properbrew - 12 hours ago

This is extremely useful, will be added to the toolbox. Thanks for sharing.

pranshuparmar - 8 minutes ago

Thank you, please feel free to share any feedback/ideas.

fracus - 11 hours ago

I really like this. Something like this should already exist, stock.

pranshuparmar - 7 minutes ago

Thanks! Funny enough, that was my thought too when creating it.

q2dg - 16 hours ago

pstree doesn't answer the why?

mathfailure - 16 hours ago

No, it does not.
- tatref - 2 hours ago
  
  I'm on mobile, so it's not super easy to read the source, but it seems like it only checks for the parent processes?
  Also I don't think this approach works correctly, because a disowned/nohup process will show up as PPID 1 (systemd), which is not correct
  - pranshuparmar - 28 minutes ago
    
    Yes, this is a bug. Planning to fix it soon.

wyldfire - 13 hours ago

`ps uaxf` gives me pretty similar output.

pranshuparmar - 25 minutes ago

`witr` is trying to be a bit different. Here are few use cases to consider: - When a process started. - Which ports a process is using. - Which user started it. - From which directory it started. - env flag to list all the variables attached to the process. - json flag to use it programmatically.

Saris - 17 hours ago

This looks very handy to have around!

pranshuparmar - 24 minutes ago

Thank you.

dontdieych - 16 hours ago

Nice and installed then starred.

pranshuparmar - 23 minutes ago

Thank you, please feel free to share any feedback/ideas.

canxerian - 17 hours ago

Great idea!

pranshuparmar - 23 minutes ago

Thank you.

pcdoodle - 11 hours ago

[dead]

tototrains - 7 hours ago

Worth mentioning: I had claude code find a crypto miner on an infected system which had been running for ~5 months undetected. Up-to-date windows 10 machine. Single prompt saying "This PC is using too much power or fans, investigate". Took minutes, completely cleaned up the infection (I hope) and identified its source. Fantastic use-case.

jbnorth - 7 hours ago

You’re better off wiping and reinstalling the OS than trying to clean the system.
da_grift_shift - 5 hours ago

>I hope