# Coding Challenge #121 - Dd

DevFeed: [Coding Challenge #121 - Dd](<https://devfeed.tech/articles/coding-challenge-121-dd-29197.md>)

Original publisher: [Read original article](<https://codingchallenges.substack.com/p/coding-challenge-121-dd>)

Author: John Crickett

Published: 2026-05-23T08:00:59Z

Content type: tutorial

Language: en

Sources: [Coding Challenges](<https://devfeed.tech/sources/coding-challenges.md>)

Topics: [Code Challenge](<https://devfeed.tech/topics/code-challenge.md>), [Unix](<https://devfeed.tech/topics/unix.md>), [coding](<https://devfeed.tech/topics/coding.md>), [Programming](<https://devfeed.tech/topics/programming.md>), [Software](<https://devfeed.tech/topics/software.md>), [Mainframe](<https://devfeed.tech/topics/mainframe.md>)

Tags: [coding](<https://devfeed.tech/tags/coding.md>), [mainframe](<https://devfeed.tech/tags/mainframe.md>), [programming](<https://devfeed.tech/tags/programming.md>), [programming-language](<https://devfeed.tech/tags/programming-language.md>), [testing](<https://devfeed.tech/tags/testing.md>), [unix](<https://devfeed.tech/tags/unix.md>), [usb](<https://devfeed.tech/tags/usb.md>)

## AI overview

A coding challenge asks readers to build their own version of dd, the Unix utility for copying and converting fixed-size data blocks. The article introduces dd's history, operand-based syntax, common uses, and an initial setup step for implementing and testing the tool.

## Source excerpt

This challenge is to build your own dd unix tool.