Yoctofetch documentation

This is the documentation for yoctofetch v2.0.0.

yoctofetch

Fast and low footprint system fetch tool for the Linux™ UAPI

In contrast to all the fetch tools out there which claim to be “really fast”, yoctofetch is an actually fast and tiny system fetch tool. It currently has a stripped weight of about 20kb and runs in ~200μs (yes, microseconds).

Despite its incredible performance, it still supports quite a few features:

Logos (currently only Guix and Arch—more to come)
The majority of common system information
Customization via a configuration file
- Disable output of specific system information
NO_COLOR support

Background

I came across a multitude of sys-fetch (neofetch like) tools on the web, each one claiming to be bazingly fast. This kind of prompted me to make one which actually deserves the title blazingly fast without compromising too much on features.

Also, I like minimalistic software which has a low resource foot print and is not suspectible to all these supply chain attacks that we got on the regular nowadays.

This is why this entire thing is written as a freestanding C program, meaning the only dependency is a Linux™ kernel to run on.

Motivation

Also, I like minimalistic software which has a low resource foot print and is not suspectible to all these supply chain attacks that we got on the regular nowadays.

This is why this entire thing is written as a freestanding C program, meaning the only dependency is a Linux™ kernel to run on.

Freestanding environment (no libc)

This software does not depend on a libc, which means it can be linked into a tiny, static binary.

Further advantages are that it would not be affected by a bug or security hole in glibc or any other libc implementation.

However, this also limits its platform support.

Currently the following are supported:

Linux ABI
- x86_64
- aarch64

Source code origin

All source code has been written by humans, without the assistance of LLMs (commonly refered to as “AI“).

History

This project originally started out under the name Ångströmfetch, but has been renamed since version 1.2.0.

Install

As a distro package

The Arch Linux AUR offers a stable and a git variant:

For Guix System:

guix install yoctofetch

For debian based distributions, there is a deb package available on the Codeberg releases page.

From source

# git clone and cd to checkout
./configure
make
sudo make install

Install from repository as Guix channel

Use this repository as Guix channel with the following channel configuration/introduction:

      (channel
        (name 'yoctofetch)
        (url "https://codeberg.org/Phosphenius/yoctofetch.git")
        (branch "main")
        (introduction
          (make-channel-introduction
            "259077c4909205af495edd5b5dded5b1173f0217"
            (openpgp-fingerprint
              "E504 167C B345 F93E 11AE  341C 1CDA 78BC 7F6C F294"))))

The package is called yoctofetch-git:

guix install yoctofetch-git

Usage

Simply run from your shell:

yoctofetch

Or put it in your .bashrc:

cd
echo "yoctofetch" >> .bashrc

Customization

The configuration file (usually ~/.config/yoctofetch/yoctofetch.conf) can be used to en- or disable all available output options, given that configuration file support is enabled, which is the default, but can be changed via ./configure --disable-config-file when building for some extra performance.

Per default, all options are enabled—even if there is no configuration file (support).

Performance

The actual performance depends on multiple factors, such as how yoctofetch was built and the layout of the files on the system.

Build configuration

The recommended configuration for maximum performance is something like:

./configure CC=gcc  CFLAGS="-march=x86-64-v3 -O2 -flto" LDFLAGS="-Wl,--strip-all" --disable-config-file

At this point, it is uncertain if there is any benefit to -flto. One has to experiment with the flags a bit. On my system, this yields a binary 19K in size which runs in < 230µs.

Also, -march=x86_64-v3 will not work on older CPUs and might have to be replaced with -march=native or similar.

File layout

yoctofetch expects the data in files to be in a certain order or layout and can read them faster if these expectations are met.

For the configuration file, this is usually under the control of the user and it is therefor recommended to keep the values in the configuration file in their default order.

This does not work for system files like /etc/os-release though. So performance will vary, even on the same hardware if a different Linux™ distro is installed.

Benchmarks

Run with hyperfine on a laptop with AMD Ryzen 7 5825U CPU.

Table 1. Benchmarks
Fetch	Mean (µs)	Min (μs)	Max (μs)	Relative
yoctofetch	217.6 ± 37.7	164.5	678.2	1
microfetch	884.4 ± 85.8	645.3	1431.9	4.06 ± 0.81
macchina	3100 ± 300	2600	4800	14.19 ± 2.77
uwufetch	16800 ± 600	16100	20200	77.42 ± 13.75
fastfetch	33400 ± 1500	30200	37400	153.71 ± 27.48
pfetch	89100 ± 2800	84500	96400	409.27 ± 72.11
ufetch	101200 ± 3700	98200	114500	464.91 ± 82.37
screenfetch	243900 ± 3100	24000	25000	1120.85 ± 194.94
neofetch	288200 ± 13800	270200	309100	1324.64 ± 238.35

Maintainers

Luca Kredel (luca dot kredel at web dot de)

Contributing

Open to pull requests, as long as they are written by humans and not LLMs.

See the contribution guidelines for details.

If you’ve found a bug or have a feature request, please open an issue on Codeberg.

License

All source code is provided under the terms of the GPL-3.0-or-later license.

Contribution guidelines

Open an issue before you open a pull request!

Scope

This project is kind of feature complete-ish, meaning there is still room for some, but an eye has to be kept on performance and binary size.

With these latter points being the main focus of this project, improvements in these areas are always welcome.

In other words: New features can be added if they don’t impact performance enough, performance (or size) improvements on the other hand are better.

Code style

Use clang-format to automatically format the code. This can be done via the Makefile:

make clang-format

Datatypes

Use: * int64_t for most integer types * uint64_t where applicable (e.g. binary flags) * struct string for strings if applicable

Changelog

Document your changes in the Changelog.

No LLM/AI policy

No “AI”—this means LLMs like ChatGPT, Claude etc.—must be used for coding, opening pull requests and issues.

If you do not speak English, you are free to open issues in your native language.

This policy is strict—failing to adhere to it will result in rejection of changes/issues and potentially blocking of user accounts.

Code authentication

The git checkout can be authenticated using the Guix package manager:

guix git authenticate 259077c4909205af495edd5b5dded5b1173f0217 "E504 167C B345 F93E 11AE 341C 1CDA 78BC 7F6C F294"

See also this blogpost and the Guix manual.

man pages

yoctofetch(1)

yoctofetch_config(5)

Changelog

[Unreleased]

Added

Config option to overwrite logo.
Config option to overwrite color.
Config option to overwrite logo colors.
Debian logo.
Fedora logo.
OS detection for Debian and Fedora.

Fixed

Output getting truncated.

Changed

Output of arch info from kernel to OS.

2.0.0 - 2026-04-19

Added

Config file support.
Terminal color support.

Fixed

Uptime output missing a newline sometimes.
Uptime edge cases—like exactly one hour, or less than one minute.

Changed

Environment variable and system file look ups for better performance.
Various performance improvements.

Removed

All command line arguments.