get_next_line

An easier way to read from an fd in C.

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ℹ️ About Project

The purpose of this project is to code a function that allows the user to read full lines from files. This project teaches the usage of the read() function and static variables.

This library implements the get_next_line function. This is a C function designed to read a file descriptor line by line, returning each line as a newly allocated string. It handles files, standard input, and even pipes, making it a versatile utility for reading text data.

Features:

• Reads one line at a time: Each call returns the next line, including the newline character if present.
• Handles multiple file descriptors (bonus): Supports reading from several files simultaneously.
• Efficient memory management: Allocates only what is needed for each line and frees memory appropriately.
• Works with any buffer size: The buffer size can be set via the BUFFER_SIZE macro.

Function Prototype

char *get_next_line(int fd);

Parameters:

• fd: The file descriptor to read from.

Return value:

• A pointer to the next line read
• NULL if end-of-file or error.

For detailed info, refer to this project subject.

🚀 Getting Started

Prerequisites

• GCC compiler
• Make utility
• Unix-like system (Linux, macOS, WSL)

Install prerequisites

• Debian/Ubuntu

  sudo apt install build-essential

🔧 Build

1. Clone the repository:

   git clone https://github.com/sdevsantiago/get_next_line.git
   cd Libft

2. Compile the project:

   make

3. Clean build files:

   make clean

Available Make Targets

Command	Description
make	Compiles both mandatory and bonus
make all	Same as make
make mandatory	Compiles mandatory part only (get_next_line.a)
make bonus	Compiles bonus part only (get_next_line_bonus.a)
make clean	Remove object files (*.o)
make fclean	Remove object files and binaries
make re	Clean and rebuild everything

👨‍💻 Usage

Basic Usage

1. Include the header file in your C file:

   #include "get_next_line.c"
   
   // or
   
   #include "get_next_line_bonus.c"

2. Compile your program with the library:

   cc -Wall -Wextra -Werror your_file.c path/to/get_next_line/get_next_line.a -I path/to/get_next_line/include -o your_program
   
   # or
   
   cc -Wall -Wextra -Werror your_file.c path/to/get_next_line/get_next_line_bonus.a -I path/to/get_next_line/include -o your_program

Example usage

Single file descriptor:

#include "get_next_line.h"
#include <fcntl.h>
#include <stdio.h>

int main(void)
{
    int   fd;
    char  *line;

    fd = open("path/to/file", O_RDONLY);
    while ((line = get_next_line(fd)) != NULL)
    {
        printf("%s", line);
        free(line);
    }

    close(fd);
    return (0);
}

Multiple file descritors:

#include "get_next_line_bonus.h"
#include <fcntl.h>
#include <stdio.h>

int main(void)
{
    int   fd[3]
    char  *line;

    fd[0] = open("path/to/file1", O_RDONLY);
    for (int i = 0; i < 5 && (line = get_next_line(fd[0])) != NULL; i++)
    {
        printf("%s", line);
        free(line);
    }

    fd[1] = open("path/to/file2", O_RDONLY);
    for (int j = 0; j < 5 && (line = get_next_line(fd[1])) != NULL; j++)
    {
        printf("%s", line);
        free(line);
    }

    fd[2] = open("path/to/file3", O_RDONLY);
    for (int k = 0; k < 5 && (line = get_next_line(fd[2])) != NULL; k++)
    {
        printf("%s", line);
        free(line);
    }

    while ((line = get_next_line(fd[0])) != NULL)
    {
        printf("%s", line);
        free(line);
    }
    close(fd[0]);

    while ((line = get_next_line(fd[1])) != NULL)
    {
        printf("%s", line);
        free(line);
    }
    close(fd[1]);

    while ((line = get_next_line(fd[2])) != NULL)
    {
        printf("%s", line);
        free(line);
    }
    close(fd[2]);

    return (0);
}

📏 Norminette

The code strictly complies with 42's Norminette v4:

norminette *.c *.h

More info in the official Norminette repository.

🙇‍♂️ Special thanks

• lrcouto and ayogun for creating and publishing, respectively, the 42-project-badges repository.
• gcamerli for creating the 42unlicense repository.

⚖️ License

This work is published under the terms of 42 Unlicense. This means you are free to use, modify, and share this software.