🖨️ Ft_Printf - 42 School Project

Welcome to ft_printf! 🎉 This is the second project of Rank 1 at 42 School, where we recreate the famous C library function printf. This project teaches us about variadic functions, format specifiers, and how to handle different data types in C.

This implementation supports all the mandatory conversion specifiers and provides a solid foundation for understanding how printf works under the hood. 🚀

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📂 Project Structure

ft_printf/ ├── include/ft_printf.h # Header file (.h)
├── src/ # All source files (.c)
│ ├── ft_printf.c # Main printf function
│ ├── ft_printchar.c # Character printing
│ ├── ft_printnbr.c # Integer printing
│ ├── ft_printstr.c # String printing
│ ├── ft_printptr.c # Pointer printing
│ ├── ft_printhex.c # Hexadecimal printing
│ └── ft_printuns.c # Unsigned integer printing
├── libft/ # Libft library
├── .gitignore
├── Makefile # Makefile to compile the project
└── README.md # This file

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📜 Implemented Features

🎯 Supported Format Specifiers

• %c - Character: Prints a single character
• %s - String: Prints a string of characters
• %p - Pointer: Prints a pointer address in hexadecimal format
• %d - Decimal: Prints a signed decimal integer
• %i - Integer: Prints a signed decimal integer
• %u - Unsigned: Prints an unsigned decimal integer
• %x - Hexadecimal (lowercase): Prints an unsigned integer in lowercase hexadecimal
• %X - Hexadecimal (uppercase): Prints an unsigned integer in uppercase hexadecimal
• %% - Percent: Prints a literal percent sign

🔧 Core Functions

• ft_printf: Main function that mimics the behavior of printf
• ft_printchar: Handles character output (%c)
• ft_printstr: Handles string output (%s)
• ft_printnbr: Handles signed integer output (%d, %i)
• ft_printuns: Handles unsigned integer output (%u)
• ft_printhex: Handles hexadecimal output (%x, %X)
• ft_printptr: Handles pointer address output (%p)

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🛠️ How to Use

📦 Compilation

To compile the library, run the following command in the root of the project:

make

This will generate a libftprintf.a file that you can link in your projects.

🧩 Include in Your Project

To use ft_printf in your project, include the header file and link the library:

#include "ft_printf.h"

And compile your project with:

gcc -Wall -Wextra -Werror -Iinclude -L. -lftprintf your_program.c -o your_program

💡 Usage Example

#include "ft_printf.h"

int main(void)
{
    int num = 42;
    char *str = "Hello, World!";
    char c = 'A';
    void *ptr = #
    
    ft_printf("Character: %c\n", c);
    ft_printf("String: %s\n", str);
    ft_printf("Integer: %d\n", num);
    ft_printf("Unsigned: %u\n", (unsigned int)num);
    ft_printf("Hex (lower): %x\n", num);
    ft_printf("Hex (upper): %X\n", num);
    ft_printf("Pointer: %p\n", ptr);
    ft_printf("Percent: %%\n");
    
    return (0);
}

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🎯 Key Learning Objectives

• Variadic Functions: Understanding how to work with functions that accept a variable number of arguments
• Format Parsing: Learning to parse and interpret format specifiers
• Data Type Conversion: Converting different data types to their string representations
• Memory Management: Proper handling of memory and avoiding leaks
• Modularity: Building a well-structured, modular codebase

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✅ Project Requirements

• ✅ Implement ft_printf function
• ✅ Support all mandatory format specifiers: c, s, p, d, i, u, x, X, %
• ✅ Return the number of characters printed
• ✅ Handle edge cases (NULL pointers, etc.)
• ✅ No memory leaks
• ✅ Compile with -Wall -Wextra -Werror

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🚀 Technical Details

This implementation uses:

• Variadic arguments (va_list, va_start, va_arg, va_end)
• Custom helper functions for each format specifier
• Modular design for easy maintenance and testing
• Integration with libft for utility functions

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Made with ❤️ at 42 Madrid