ft_printf

A recreation of the C standard library printf function with support for various format specifiers.

Description

ft_printf is a project that involves recreating the famous printf function from the C standard library. This project teaches you about variadic functions, format parsing, and proper output formatting. It handles multiple data types and conversion specifiers.

Features

• Supports major format specifiers: %c, %s, %p, %d, %i, %u, %x, %X, %%
• Handles variadic arguments
• Proper conversion and formatting
• Memory-safe implementation
• Compatible with the original printf behavior

Function Prototype

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

Supported Format Specifiers

• %c: Character
• %s: String
• %p: Pointer address (hexadecimal)
• %d: Signed decimal integer
• %i: Signed integer
• %u: Unsigned decimal integer
• %x: Hexadecimal integer (lowercase)
• %X: Hexadecimal integer (uppercase)
• %%: Literal % character

Compilation

make

This creates a libftprintf.a static library.

Usage

1. Clone the repository:

git clone https://github.com/bratzwitch/ft_printf.git
cd ft_printf

2. Compile the library:

make

3. Include in your project:

#include "ft_printf.h"

4. Compile your program:

gcc -Wall -Wextra -Werror your_file.c -L. -lftprintf

Example Usage

#include "ft_printf.h"

int main()
{
    int num = 42;
    char *str = "Hello";
    void *ptr = #
    
    ft_printf("Character: %c\n", 'A');
    ft_printf("String: %s\n", str);
    ft_printf("Pointer: %p\n", ptr);
    ft_printf("Decimal: %d\n", num);
    ft_printf("Hexadecimal: %x\n", num);
    ft_printf("Uppercase hex: %X\n", num);
    ft_printf("Unsigned: %u\n", 3000000000U);
    ft_printf("Percentage: %%\n");
    
    return (0);
}

Return Value

Returns the number of characters printed (excluding the null terminator).

Files Structure

• ft_printf.c: Main function implementation
• ft_printf_utils.c: Helper functions for conversions
• ft_printf.h: Header file with prototypes
• Makefile: Compilation rules

Implementation Details

• Uses write() system call for output
• Handles edge cases (NULL pointers, zero values)
• Proper memory management
• No global variables used
• Follows 42 Norm coding standards

Requirements

• GCC compiler
• Make
• Standard C library headers

Testing

#include "ft_printf.h"
#include <stdio.h>

int main()
{
    int ret1, ret2;
    
    ret1 = ft_printf("ft_printf: %d %s %x\n", 42, "test", 255);
    ret2 = printf("printf:    %d %s %x\n", 42, "test", 255);
    
    printf("ft_printf returned: %d\n", ret1);
    printf("printf returned:    %d\n", ret2);
    
    return (0);
}

Author

Viacheslav Moroz - 42 Student