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Eric Radman
Personal blog · eradman.com/postssystemsprogramming
Eric Radman's personal blog at eradman.com covers systems and programming. Since 2017, 37 different Hacker News readers have linked it 42 times, most often “Entr: Run arbitrary commands when files change”. It is still writing: the last post was on 2026-10-16, and you can follow it by feed.
Too few sampled comments (28) to say how often HN recommends it.?
Why HN links it
HN readers link Eric Radman's site mainly for entr, his file watcher that reruns a command when files change, and its man page and online docs. Related tools such as ephemeralpg also come up.
- Recommended for · 2 comments
- Commenters call the entr man page and online reference great, say to check the man page, and call entr great software that does what it should.
Summarised by Claude from a sample of 28 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Most-linked posts?
- Entr: Run arbitrary commands when files change19 people · 21 mentions · first linked 2018-12-25
- Entr(1) – Run arbitrary commands when files change9 people · 9 mentions · first linked 2020-04-15
- Pg_tmp – Run tests on an isolated, temporary PostgreSQL database2 people · 2 mentions · first linked 2021-04-26
What Hacker News says?
For markdown I don't use/need a plugin, with entr[0] and Pandoc you can emulate the live preview feature easily, without even needing a browser. 0: http://eradman.com/entrproject/
Comment linking /entrproject/
on “The Era of Visual Studio Code”Submitted Pg_tmp – Run tests on an isolated, temporary PostgreSQL database as a story · 181 points
HN discussionProbably git, 1password (though I'm planning to shift to Bitwarden), and entr: http://eradman.com/entrproject/ Having a simple standard way to automate all of my modify->"do x" runs has been wonderful, and (with a bit of care in your project structure) being able to near-livecode in almost any language is an incredible productivity boost.
Comment linking /entrproject/
on “Ask HN: Programs that saved you 100 hours?”Submitted Ephemeral Postgres Databases as a story · 88 points
HN discussionis `dotnet watch` basically `git ls-files|entr dotnet build` ? (entr is http://eradman.com/entrproject/ – like inotifywait but easier)
Comment linking /entrproject/
on “Despite best efforts .NET is still not an open platform”Submitted Test-Driven Development in C as a story · 3 points
HN discussionHa! I took too long to format my response :). The entr examples from [1] seem to do the same (ls *.rb for example). [1] http://eradman.com/entrproject/
Comment linking /entrproject/
on “My one-liner Linux Dropbox client”Submitted FreeBSD Bhyve and iPXE as a story · 2 points
HN discussionWe use this for TypeScript development at my company. Using swc for transpilation reduces build time from ~10s (small-ish codebase) to near instant. We can then wrap it in entr [1] to get live API reloading for free. For type checking, you can run the TypeScript compiler in another window in watch mode, or just rely on editor warnings until the code hits CI. [1]: https://eradman.com/entrproject/
Comment linking /entrproject/
on “Next.js 12”Submitted Automated FreeBSD Install as a story · 2 points
HN discussionYou can usually script the database setup and teardown and have the test suite use the same scripts you have available in a nix-shell. pg_tmp [1] also helps http://eradman.com/ephemeralpg/
Comment linking /ephemeralpg/
on “Can we trust Microsoft with open source?”Submitted Entr(1) – Run arbitrary commands when files change as a story · 2 points
HN discussionI can't sing the praises enough of entr. Just check out its man page: http://eradman.com/entrproject/ entr lets you watch files and re-run a command any time they change. Whenever I'm working on a script, or go tests, or whatever test-like thing I'm doing that's not in its own bloated test harness, I reach for entr. Great software, does what it's supposed to every time.
Comment linking /entrproject/
on “Command line tools for productive programmers”Submitted Entr: Run arbitrary commands when files change as a story · 2 points
HN discussionTo emulate the live preview, there is a neat piece of software called entr[1], from their main page, you can do something like: ls | entr make And whenever you save a change, the build is triggered and the preview is updated. [1]: http://eradman.com/entrproject/
Comment linking /entrproject/
on “Writing a Book with Pandoc, Make, and Vim”Submitted Entr: Run arbitrary commands when files change as a story · 2 points
HN discussionSee also: * entr(1) - http://eradman.com/entrproject/ * Watchexec - https://watchexec.github.io/
Comment linking /entrproject/
on “Ask HN: Can I see your scripts?”Submitted Running a Linux VM on OpenBSD as a story · 2 points
HN discussionMay I suggest to look at https://eradman.com/entrproject/ ? It's like watch but triggers only when it detect file changes.
Comment linking /entrproject/
on “IPython 8.0”Submitted ZFS Quickstart as a story · 1 points
HN discussionLots of ways! So this is one of those things that's subtly quite interesting -- Make will both take all variables from the environment, and make them Make variables. So this command: $ USER=my_name make psql The above example is the creation of a temporary ENV variable (assuming your shell supports this feature, it's equivalent to doing an export but only for that line), and the USER variable (accessed by using $(US…
Comment linking /entrproject/
on “Starting a TypeScript Project in 2021”Submitted A stabilized approach to systems orchestration (2020) as a story · 1 points
HN discussionThat's literally in the article; `entr -d`. The manpage also has an entry. http://eradman.com/entrproject/entr.1.html#d
Comment linking /entrproject/entr.1.html
on “Entr: Rerun your build when files change”Submitted Entr – tool for watching files and running commands as a story · 1 points
HN discussiondependency free, solid design, perfect with tmux, great online reference. does not try to do magic: http://eradman.com/entrproject/
Comment linking /entrproject/
on “Entr: Rerun your build when files change”Submitted entr – Event Notify Test Runner as a story · 1 points
HN discussionentr is cross-platform and utilizes the best of the platforms it runs on. Also, the docs are explaining the problems with inotify: http://eradman.com/entrproject/
Comment linking /entrproject/
on “Entr: Rerun your build when files change”Submitted Handling TCP Connections with Kqueue Event Notification (2018) as a story · 1 points
HN discussionThe author is Eric Radman. The visionary behind the entr(1) file watcher http://eradman.com/entrproject/ GitHub: https://github.com/eradman , also: rset(1): http://scriptedconfiguration.org/ - Configure systems using any scripting language
Comment linking /entrproject/
on “Pg_tmp – Run tests on an isolated, temporary PostgreSQL database”https://eradman.com/ephemeralpg/ (for Postgres) plus making sure your test suite is parallel works wonders.
Comment linking /ephemeralpg/
on “Database mocks are not worth it”
