sample.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   sample.c                                           :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: lsauvage <lsauvage@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2018/02/07 18:30:58 by lsauvage          #+#    #+#             */
/*   Updated: 2018/02/14 16:47:58 by lsauvage         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

int     readlinewidth(int fd)
{
    char    buff[2];
    size_t  nbread;

    (void) memset((void *) buff, 0, (size_t) 2);
    nbread = read(fd, (void *) buff, (size_t) 2);
    if (nbread <= 0)
        return (-1);
    buff[1] = '\0';
    return (atoi(buff));
}

void    readandprintlines(int fd, size_t linewidth)
{
    char    *buff;
    size_t  nbread;

    buff = (char *) malloc(sizeof(*buff) * (linewidth + 1));
    if (buff == NULL)
        return ;
    (void) memset((void *) buff, 0, linewidth + 1);
    while ((nbread = read(fd, (void *) buff, linewidth)) != 0)
    {
        printf("%s", buff);
        (void) memset((void *) buff, 0, linewidth);
    }
    free(buff);
    return ;
}

int     main(void)
{
    int     fd;
    int     linewidth;

    fd = open("./file.txt", O_RDONLY);
    if (fd == -1)
        return (-1);
    linewidth = readlinewidth(fd);
    if (linewidth == -1 || linewidth == 0)
        return (-1);
    readandprintlines(fd, (size_t) linewidth);
    close(fd);
    return (0);
}