Log File Viewer for the Terminal

(lnav.org)

229 points | by wiradikusuma 8 hours ago

16 comments

  • guessmyname 7 hours ago
    Oh yeah! lnav is famous. I remember using it like a decade ago to monitor an array of web servers while at GoDaddy; good ol' times.

    First commit is from Sep 13, 2009: https://github.com/tstack/lnav/commit/b4ec432515e95e86ec9d71... . Woah! we’re old.

    This is what the UX looked like back in the day: https://github.com/tstack/lnav/commit/bce2caa654160518ec11f6...

    • boomskats 6 hours ago
      Wow, the GitHub mobile app doesn't preview PNGs. TIL
      • ifh-hn 5 hours ago
        GitHub website does on mobile.
        • port11 43 minutes ago
          GitHub mobile requires login, sadly.
  • vdm 1 hour ago
  • rsafaya 3 hours ago
    I wish I had found this earlier. Nothing like looking at thousands of EV charger logs all day to mak you appreciate something like this.
  • p0w3n3d 7 hours ago
    This is almost the thing I want and need. What I need is some sort of TUI grafana - Json log splitter/organizer/finder
    • makapuf 6 hours ago
      Currently working exactly on that https://gitlab.com/makapuf/treewalker (even if it could always use some love)
    • aledevv 4 hours ago
      In my opinion logfile navigator is much better than grafana, I use grafana to view a lot of microservices docker logs, but it's too tedious for me (even if depends on your specific use case).

      This one, on the other hand, is cleaner and lets you find what you're looking for quickly. And, last but not least, is much lighter.

    • dima55 7 hours ago
      I use vnlog and feedgnuplot to massage and plot data on the console all the time. It's even less than a tui, but might be what you want.
      • dloss 6 hours ago
        If you're fine with CLIs, maybe my Kelora project is worth a look. It's a very flexible log processor with built-in scripting: https://kelora.dev
  • Sammi 4 hours ago
    This looks great.

    I've been using klogg and if you're more into GUI's then I think it's the best there is. It opens and searches in log files of many gigabytes with easy. It's a simple and clean multiplatform QT app.

    https://github.com/variar/klogg

    • graemep 4 hours ago
      The problem with GUIs is that AFAIK they need to be installed on the machine the logs you are reading are on so a heavy install on a server.
  • elcapitan 5 hours ago
    > ssh playground@demo.lnav.org

    Really appreciate this way to demo it quickly, very nice!

  • brunosutic 6 hours ago
    I tried lnav about 7-8 years ago and as a terminal junkie I really liked the features.

    The only breaking thing was a huge (almost bloated) memory consumption. At that time lnav basically just kept everything in memory. Does anyone did that change?

    • xx_ns 6 hours ago
      According to the linked homepage, the memory usage seems decent (few hundred megs for most use cases when working with a 3.3G logfile). There's a screenshot with various tasks and what the peak memory usage is.

      At some point you need to keep quite a large context in memory to have both decent performance and useful features (that aren't unbearably slow to use). lnav seems to land at a reasonable middle ground.

  • asmosoinio 7 hours ago
    Looks very useful, will give it a go.

    This resonates with my use of grep+less: https://github.com/tstack/lnav?tab=readme-ov-file#why-not-ju...

  • __bax 5 hours ago
    Must have tool!
  • steveharing1 6 hours ago
    I was looking for something like this, Appreciate it!
  • vincentabolarin 4 hours ago
    This looks genuinely useful.
  • yagelar 4 hours ago
    very nice, definitely will use it
  • worksonmine 3 hours ago
    It's a nice tool but I really wish the configuration wasn't done in json and loaded from $XDG_CONFIG_HOME.
  • Duke64 2 hours ago
    I'm a little disappointed that it's not written in Rust.
    • emmelaich 1 hour ago
      I sense an opportunity for you.
  • leontloveless 2 hours ago
    [dead]
  • teh 2 hours ago
    Super useful tool but need to be aware that this is reading potentially untrusted input (e.g. in the case of http request logs) and written in c++, so a possible attack vector. I use lnav where I trust the logs, but do wish a safe implementation existed.
    • fireflash38 1 hour ago
      Memory safety doesn't mean it's safe. And C++ doesn't mean it's unsafe.

      Browsers are in C++, do you not use them? Curl is in C, do you not use it? Kernel is C...

      • teh 30 minutes ago
        Chrome uses sandboxing and a lot of safe tooling (wuffs, rust) for untrusted data.

        curl is heavily fuzzed and you still mostly control what you are downloading unless the target is compromised.

        With logs the attacker controls what goes into your logs.

        And you don't need to really look very hard, there are a fair number of very recent stack and heap overflows: https://github.com/tstack/lnav/issues?q=is%3Aissue%20heap%20...