libft

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A comprehensive C library containing reimplementations of standard C library functions, plus additional utility functions for string manipulation, memory management, linked lists, and formatted output.

📋 Table of Contents

• About
• Features
  • Part I - Standard C Library Functions
  • Part II - Additional String Functions
  • Part III - Linked Lists
  • Printf Implementation
  • Get Next Line
• Installation
  • Prerequisites
  • Build
• Usage
  • Include in your project
  • Link with your program
  • Example usage
• Project Structure
• Testing
• Performance
• Function Categories
• Compilation Flags
• Forbidden Functions
• Key Features
• Contributing
• License
• Author

📚 About

libft is a custom C library developed as part of the 42 School curriculum. It provides essential functions for C programming, including:

• Standard C library function reimplementations
• Additional utility functions for string and memory operations
• Linked list manipulation functions
• Custom printf implementation with file descriptor support
• get_next_line function for reading files line by line

🚀 Features

Part I - Standard C Library Functions

• Character checks: ft_isalpha, ft_isdigit, ft_isalnum, ft_isascii, ft_isprint
• String functions: ft_strlen, ft_strchr, ft_strrchr, ft_strncmp, ft_strnstr
• Memory functions: ft_memset, ft_memcpy, ft_memmove, ft_memchr, ft_memcmp
• String copying: ft_strlcpy, ft_strlcat
• Character conversion: ft_toupper, ft_tolower
• String to integer: ft_atoi, ft_atol
• Memory allocation: ft_calloc, ft_bzero
• String duplication: ft_strdup

Part II - Additional String Functions

• String manipulation: ft_substr, ft_strjoin, ft_strtrim, ft_split
• Number to string: ft_itoa, ft_itoa_base
• String iteration: ft_strmapi, ft_striteri
• File descriptor output: ft_putchar_fd, ft_putstr_fd, ft_putendl_fd, ft_putnbr_fd

Part III - Linked Lists

typedef struct s_list
{
    void            *content;
    struct s_list   *next;
} t_list;

• List operations: ft_lstnew, ft_lstadd_front, ft_lstadd_back
• List utilities: ft_lstsize, ft_lstlast
• List manipulation: ft_lstdelone, ft_lstclear, ft_lstiter, ft_lstmap

Printf Implementation

Custom ft_printf function with support for:

• Format specifiers: %c, %s, %d, %i, %u, %x, %X, %p, %%
• Flags: -, 0, #, , +
• Width and precision: *, .
• File descriptor version: ft_printf_fd

Get Next Line

get_next_line function for reading files line by line with configurable buffer size.

🛠️ Installation

Prerequisites

• GCC or any C compiler
• Make

Build

# Clone the repository
git clone https://github.com/yourusername/libft.git
cd libft

# Compile the library
make

# Clean object files
make clean

# Clean everything
make fclean

# Recompile
make re

📖 Usage

Include in your project

#include "libft.h"

Link with your program

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

Example usage

#include "libft.h"

int main(void)
{
    // String functions
    char *str = ft_strdup("Hello, World!");
    char **split = ft_split(str, ' ');

    // Linked list
    t_list *list = ft_lstnew("First");
    ft_lstadd_back(&list, ft_lstnew("Second"));

    // Printf
    ft_printf("Number: %d, String: %s\n", 42, "libft");

    // Memory cleanup
    free(str);
    // ... free split array and list

    return (0);
}

📁 Project Structure

libft/
├── Makefile                 # Build configuration
├── libft.h                 # Main header file
├── ft_printf.h             # Printf header file
├── get_next_line.h         # Get next line header file
├── README.md               # This file
├── .gitignore             # Git ignore rules
├── ft_*.c                 # Function implementations
└── obj/                   # Object files (created during build)

🧪 Testing

The library has been thoroughly tested with:

• Custom test suites
• 42 School testers
• Memory leak detection with Valgrind
• Edge cases and error handling

⚡ Performance

• Optimized algorithms for memory operations
• Efficient string manipulation
• Minimal memory footprint
• No unnecessary function calls

📊 Function Categories

Category	Functions	Description
Character Tests	5 functions	Check character properties
String Operations	15+ functions	String manipulation and analysis
Memory Management	8 functions	Memory allocation and manipulation
Linked Lists	9 functions	Dynamic data structure operations
File I/O	6 functions	File descriptor operations
Printf	15+ functions	Formatted output implementation
Utilities	10+ functions	Helper and conversion functions

🔧 Compilation Flags

The library is compiled with strict flags to ensure code quality:

-Wall -Wextra -Werror

🚫 Forbidden Functions

This implementation doesn't use any external libraries except for:

• malloc, free (memory management)
• write (system call)
• Standard library headers for type definitions

💡 Key Features

• Memory Safe: All functions handle edge cases and prevent buffer overflows
• Norm Compliant: Follows 42 School coding standards
• Well Documented: Each function includes comprehensive documentation
• Modular Design: Functions can be used independently
• Performance Optimized: Efficient algorithms and minimal overhead

🤝 Contributing

This is an educational project for 42 School. While not accepting external contributions, feel free to:

• Report bugs
• Suggest improvements
• Use as a reference for your own implementation

📜 License

This project is part of the 42 School curriculum and follows their academic guidelines.

👨‍💻 Author

joamiran - 42 Lisboa Student

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This library represents a comprehensive foundation for C programming, providing essential tools for memory management, string manipulation, and formatted output while maintaining high code quality standards.