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A file-based IRC client inspired by ii(1).


I originally only intended to write a frontend for ii instead of completely rewriting it from scratch. However, while working on the frontend I noticed that I couldn't implement certain features in the frontend without changes to the backend (ii). I briefly considered patching ii but ultimately decided for a rewrite.

During the rewrite various features have been implemented which could have been moved to separate tools, such as TLS support, hence the name harmful ii (hii).


I currently consider hii feature complete and use it myself regularly in combination with insomnia and a per-server runit user service for starting hii.


New features (compared to ii):

  • Memory safety
  • A proper IRC protocol implementation through girc
  • Support for automatically joining channels on startup
  • Support for IRCv3.2 monitoring
  • Support for a per-channel nick list using a UNIX domain socket
  • Support for recording messages mentioning the users
  • Support for authentication using TLS client certificates (CertFP)
  • Built-in TLS support
  • Built-in IPv6 support

Features intentionally not implemented:

  • Automatic authorization using the PASS command is not implemented (ii -k flag).
  • Shortcut commands, e.g. /j. If you need them write yourself a shell script for mapping shortcut commands to real commands.

While hii has more features than ii it is still supposed to have a limit feature set and shouldn't "expand until it can read mail".

Compatibility with ii

Backwards compatibility with ii wasn't a goal. While the directory structure is mostly backwards compatible everything else is pretty much different. This is the case because proper backwards compatibility would have been a lot of work and I personally didn't need it.


The program can be installed either using go install or make.

go install

To install to the program using go install run the following command:

$ go install

Note that this will not install additional documentation files, e.g. man pages.


To install to the program using make run the following commands:

$ git clone
$ cd hii
$ make && make install

This will also install documentation files to the correct location and may thus be preferable when packaging this software for a distribution.


Q: Sockets cannot be used with standard utilities such as grep(1). Why are nick names served using a unix domain socket anyhow?

A: Several ways of implementing a nick list have been considered. Using a regular file has various obvious disadvantages. For instance, the file would need to be truncated every time the nick list changes, which causes a lot of file system operation. Using a FUSE for serving the nick list was also briefly considered, however, while this would allow interaction with standard utilities it would require linking against FUSE and would complicate things quite a bit. Serving nicks using a unix domain socket seemed to be a reasonable compromise.

Q: Why are mentions recorded in a separate file? Can't this be implemented using inotify, kqueue, … in the frontend?

A: While this might certainly be possible it would complicate the frontend code quite a bit. Implementing this in the backend was fairly easy and only required a few changes. Additionally, neither kqueue nor inotify are mandated by POSIX.

Q: Can feature X/Y/Z be added to hii?

A: No.


This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see