HackerReposA FIELD GUIDE TO OPEN SOURCE
ProSponsor the shelf♧ 0
← Back to top all-time
e-dant
watcher
C++2022–2026
e-dant / watcher

watcher

Filesystem watcher. Works anywhere. Simple, efficient and friendly.

4Distinct people
12Mentions
0Explicit recommenders
808GitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Filesystem watcher. Works anywhere. Simple, efficient and friendly.

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 1:49:46 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year12 dated mentions

Observed mentions: 2022-10-05 15:44:17 UTC to 2026-03-28 21:29:43 UTC.

02468102022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 10 mentions; 1 submissions, 9 comments20222023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 1 mentions; 1 submissions, 0 comments20242025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2026-01-01 00:00:00 UTC to 2027-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments. Incomplete calendar period.2026*

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC1019
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC000
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC110
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC000
2026 (partial)2026-01-01 00:00:00 UTC2027-01-01 00:00:00 UTC101

What Hacker News says

12 sources
Since there are comments below asking about benchmarks, others noting or expressing interest in other projects, I'll drop the one I made: https://github.com/e-dant/watcher (and also an ebpf experiment https://github.com/e-dant/bpf-fs-events) There are benchmarks in there, and comparisons with all the other watchers out there I could find at the time I made it (see "Comparison with Similar Projects" at the very bottom of the readme). It's a pretty long list. Tons of watchers out there with different design philosophies and shapes of problems they solve. There are a lot of caveats to the filesystem monitoring APIs provided by kernels. Some projects (like facebook's watchman) take that as a kind of antagonism, and decide to fight back with layers and layers of fallbacks and distrust and rescans. That projects basically only makes sense as a
Read the rest
daemon. Other programs and libraries try to take that complexity and tame it by being super-focused on one platform or providing a lot of configuration options. Some provide debouncing logic. This particular feature comes up from time to time, I believe, both for practical reasons and because over-reported events from the kernel subsystems, especially for some arcane events like moving a file across mount points can trigger a flurry of hard-to-associate events for the same path. If you want to avoid dealing with under-documented filesystem event subsystems, you can also just make your own with ebpf. Especially for security-oriented systems, you'll find that the only (nearly) perfectly accurate filesystem event subsystem you can make, is the one you make from the ground up.
In Detecting file changes on macOS with kqueue
e-dant·Oct 18, 2022Submission

Show HN: Filesystem Watcher

An arbitrary filesystem event watcher which is: - simple - efficient - dependency free - runnable anywhere with a filesystem - header only Watcher is extremely efficient. In most cases, even when scanning millions of paths, this library uses a near-zero amount of resources. Watcher is simple. The library exposes a single function and a single object. That is all. Happy hacking.
91 points · Open discussion

MAKE YOURSELF AT HOME

A few shortcuts

/
Search the collection
?
Open this guide
Esc
Close dialogs and navigation

Your saved repositories and interests stay in this browser.