ft_printf — Custom printf Implementation in C

42 Urduliz — Common Core project

A reimplementation of the C standard library printf function, handling the most common format specifiers.

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Supported Conversions

Specifier	Output
%c	Single character
%s	String
%p	Pointer address (hex)
%d / %i	Signed decimal integer
%u	Unsigned decimal integer
%x / %X	Hexadecimal (lower/upper)
%%	Literal percent sign

Build & Use

make
# Links as a static library: libftprintf.a

Include in your project:

#include "printflib.h"
ft_printf("Hello %s, you are %d years old\n", name, age);

Implementation

Uses variadic functions (va_list, va_arg) to handle variable argument lists. Each format specifier is dispatched to a dedicated handler function.

Skills

C Variadic Functions String Formatting Static Library Makefile

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Academic Integrity

This repository is shared for educational and portfolio purposes only.

For 42 students:

• Do not copy this code for your own project submissions
• Use it as a reference to understand concepts and approaches
• Write your own original solution — that is the only way to actually learn

42's core values are learning through practice, peer collaboration, and genuine problem-solving.

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License

MIT — see LICENSE for details. Copyright (c) 2026 Eneko Muñoz Bordona