42 Common Core

Rebuilding libc, printf and getline from scratch at 42, and how each one was tested.

Project overview: CodeTester — An Interactive C Tester for 42 Projects

1. 
   Deep dive Systems & Low-Level

   42 Common Core — Libft: Rebuilding the C Standard Library

   Re-implementing libc string, memory and list functions from scratch, and the edge cases that matter: overlapping copies, size-bounded strings and allocation failures

   Oct 2026 · C· Linux
2. 
   Deep dive Systems & Low-Level

   42 Common Core — ft_printf: Variadic Functions and Format Parsing

   Recreating printf with va_list, a small format parser and a single layout function for flags, width and precision

   Oct 2026 · C· Linux
3. 
   Deep dive Systems & Low-Level

   42 Common Core — get_next_line: Reading a File One Line at a Time

   Buffered reads, static state between calls and a linked list of chunks, plus the bonus: several file descriptors at once

   Oct 2026 · C· Linux