🖨️ ft_printf

📝 Introduction

ft_printf is a 42 School project that involves recoding the famous C library function printf(). This project is an opportunity to discover variadic functions and improve code organization through a complex task.

"By reimplementing printf, you'll learn about handling multiple types of arguments, string formatting, and precise memory management."

The primary goal is to create a function that mimics the behavior of the standard printf function, handling various format specifiers and conversion options.

🎯 Project Objectives

• Implement a function that formats and prints data to stdout
• Handle variable arguments in C
• Process multiple format specifiers
• Develop a robust string parsing mechanism
• Apply proper memory management techniques

📋 Function Prototype

int ft_printf(const char *format, ...);

✅ Implemented Format Specifiers

Specifier	Description	Example
%c	Single character	ft_printf("%c", 'X') → X
%s	String of characters	ft_printf("%s", "hello") → hello
%p	Pointer address in hexadecimal	ft_printf("%p", ptr) → 0x7ffeeb9a52e0
%d	Decimal (base 10) integer	ft_printf("%d", 42) → 42
%i	Integer in base 10	ft_printf("%i", 42) → 42
%u	Unsigned decimal integer	ft_printf("%u", 42) → 42
%x	Hexadecimal (base 16) lowercase	ft_printf("%x", 42) → 2a
%X	Hexadecimal (base 16) uppercase	ft_printf("%X", 42) → 2A
%%	Percent sign	ft_printf("%%") → %

🧩 Project Structure

The project consists of three main files:

ft_printf/
├── Makefile
├── ft_printf.c       # Main implementation with helper functions
├── ft_printf_ptr.c   # Functions for handling pointer printing
└── ft_printf.h       # Header with prototypes and hex strings

🛠️ Code Explanation

ft_printf.h

This header file includes:

• Function prototypes for all functions in the project
• Hexadecimal string definitions for lowercase and uppercase
• Standard library includes (unistd.h, stdarg.h)
• Custom libft.h library include

ft_printf_ptr.c

Contains specialized functions for handling pointer arguments:

Function	Description
ft_write_ptr	Recursively writes a pointer's hexadecimal representation
ft_print_ptr	Manages pointer output formatting - prints "(nil)" for NULL or "0x" prefix followed by address

ft_printf.c

Contains the main function and helper functions:

Function	Description
ft_print_hex	Converts and prints unsigned integer in hexadecimal (lowercase or uppercase)
ft_print_unsigned	Handles printing of unsigned integers
ft_is_format	Analyzes format specifier and routes to appropriate handler function
ft_printf	Main function that parses format string and processes variable arguments

🧠 Skills Developed

• Working with variadic functions in C
• Advanced string parsing and formatting
• Type conversion and handling
• Code organization in a modular structure
• Recursive implementation techniques
• Memory efficiency in string handling

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📊 Project Stats

Metric	Value
Final Score	100/100
Format Specifiers	9
Files	3
Dependencies	libft