A terminal application to view, tail, merge, and search log files (plus JSONL).

See Toolong on Calmcode.io for a calming introduction to Toolong.

• Live tailing of log files.
• Syntax highlights common web server log formats.
• As fast to open a multiple-gigabyte file as it is to open a tiny text file.
• Support for JSONL files: lines are pretty printed.
• Opens .bz and .bz2 files automatically.
• Merges log files by auto detecting timestamps.

I spent a lot of time in my past life as a web developer working with logs, typically on web servers via ssh. I would use a variety of tools, but my goto method of analyzing logs was directly on the server with *nix tools like as tail, less, and grep etc. As useful as these tools are, they are not without friction.

I built toolong to be the tool I would have wanted back then. It is snappy, straightforward to use, and does a lot of the grunt work for you.

Toolong is currently best installed with pipx.

pipx install toolong

You could also install Toolong with Pip:

pip install toolong

However you install Toolong, the tl command will be added to your path:

tl

In the near future there will be more install methods, and hopefully your favorite package manager.

Toolong works on Linux and macOS. I don't think it will work on Windows yet, but it could. Let me know if you would like Windows support.

To open a file with Toolong, add the file name(s) as arguments to the command:

tl mylogfile.log

If you add multiple filenames, they will open in tabs.

Add the --merge switch to open multiple files and combine them in to a single view:

tl access.log* --merge

In the app, press f1 for additional help.

This guy. An ex web developer who somehow makes a living writing terminal apps.

If you follow me on Twitter, you may have seen me refer to this app as Tailless, because it was intended to be a replacement for a tail + less combo. I settled on the name "Toolong" because it is a bit more apt, and still had the same initials.

Toolong v1.0.0 has a solid feature set, which covers most of my requirements. However, there is a tonne of features which could be added to something like this, and I will likely implement some of them in the future.

If you want to talk about Toolong, find me on the Textualize Discord Server.

I am grateful for the LogMerger project which I referenced (and borrowed regexes from) when building Toolong.

Toolong is not the first TUI for working with log files. See lnav as a more mature alternative.