🖨️ ft_printf

A C reimplementation of printf, built as part of the 42 School curriculum.

This project explores variadic functions, format parsing, and writing formatted output while returning the number of characters printed.

🎯 About the project

ft_printf reads a format string, retrieves each matching argument with stdarg.h, prints the value, and returns the total output length. The implementation is packaged as the reusable static library libftprintf.a.

✨ Supported conversions

Conversion	Output
%c	A character
%s	A string ((null) for a null pointer)
%p	A pointer address in hexadecimal with a 0x prefix
%d, %i	A signed integer
%u	An unsigned integer
%x, %X	A lowercase or uppercase hexadecimal integer
%%	A literal percent sign

🧠 Key concepts

• 🎭 Variadic arguments with va_list, va_start, va_arg, and va_end
• 🔎 Parsing a format string and dispatching to conversion functions
• 🔢 Converting signed, unsigned, hexadecimal, and pointer values to text
• 📏 Counting the characters written and returning the total
• 📦 Building a reusable static library with Make

🛠️ Requirements

• A C compiler such as cc or gcc
• make

🚀 Build

git clone <repository-url>
cd printf
make

The build creates libftprintf.a in the project directory.

💡 Example

#include "ft_printf.h"

int main(void)
{
    int printed;

    printed = ft_printf("Hello, %s! Number: %d\n", "world", 42);
    return (printed < 0);
}

Compile your program with the library:

cc -Wall -Wextra -Werror -I/path/to/printf \
  main.c /path/to/printf/libftprintf.a -o app

Replace /path/to/printf with the directory containing ft_printf.h and libftprintf.a.

🧹 Makefile commands

Command	Description
make	Build libftprintf.a
make clean	Remove object files
make fclean	Remove object files and the library
make re	Clean and rebuild

🏅 42 evaluation

The project received a successful score of 104/100. The evaluation summary is included below.

👩‍💻 Author

Sedef Akkaya
GitHub · LinkedIn

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✨ Parse the format. Print the value. Count every character.