Which command-line programs are featured on david-peter.de and what do they do?

Updated

david-peter.de is the personal website of David Peter, a software developer in Stuttgart, Germany, who works on a Python type checker at OpenAI and has written a set of open-source command-line tools. The site lists six of them: fd, hyperfine, bat, hexyl, pastel, and vivid. Each replaces or improves on a familiar Unix utility, and the descriptions below come from how the site presents them.

The six tools at a glance

Tool What it does What it replaces or improves
fd A fast file-search tool with a clean, approachable command-line interface The classic find command
hyperfine Measures the execution time of other programs and helps with proper statistical analysis of the results Ad-hoc timing with time
bat A "supercharged" version of cat for reading syntax-highlighted code in the terminal cat
hexyl A terminal hex viewer that color-codes byte categories for a clearer overview Plain hex dumps
pastel A color-manipulation tool with commands for generating, analyzing, converting, and manipulating colors Manual color math
vivid Generates the LS_COLORS environment variable that controls the colorized output of ls Hand-written LS_COLORS strings

What each tool is for

fd: friendlier file search

The site describes fd as an alternative to find that focuses on both performance and a clean, approachable command-line interface. If you have ever struggled to remember find's expression syntax, fd is aimed at you. The site does not publish benchmarks or a full flag reference, so treat the performance claim as the author's stated design goal rather than a measured figure.

hyperfine: benchmarking with statistics

hyperfine measures how long other programs take to run and, per the site, helps with proper statistical analysis of the results. That makes it useful when you want to compare two implementations of the same task rather than eyeball a single run. The site does not specify which statistical methods it applies, so check the project documentation before relying on specific numbers.

bat, hexyl, pastel, vivid: reading and formatting output

These four are smaller utilities for making terminal output easier to read or control:

  • bat adds syntax highlighting when you read code with cat.
  • hexyl colorizes hex output so different byte categories stand out.
  • pastel handles color generation, analysis, conversion, and manipulation from the command line.
  • vivid builds the LS_COLORS value that tells ls how to color files.

Where to find them and what else is on the site

The site says David's open-source work is published on GitHub and his academic work on arXiv, and that he can be reached by email. Beyond the command-line tools, the page also lists:

  • Numbat (numbat.dev), a high-precision scientific calculator with full physical-unit support. It runs in the terminal and in the browser, understands SI units including metric and binary prefixes plus most US customary and imperial units, and supports user-defined variables and functions.
  • cube composer, a puzzle game inspired by functional programming in which you compose a series of transformations to arrange colored cubes into the correct pattern. It is written in PureScript.
  • quizzity and curiositY, which appear as headings on the page but are not described in the available excerpt.

The site gives no pricing information for any of these projects, so nothing here should be read as confirming they are free or require no account. For installation steps, supported platforms, and exact options, go to each project's GitHub repository or, for Numbat, numbat.dev.