get_next_line

This project aim to read a line the file description - fd (can be a file, a input or output, the fd must exist, and must have something inside this space)

How to use

The way to use this function is pretty simple, it have as parameter two variables:

• First is a integer 'fd', that is the file description, (it can be a file opened, or a standard fd: stdin, stdout, stderr);
• Second is a string where do you want to store the line found;
  

The implementation looks like this:

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

int main()
{
	int fd;
	int return_fd;
	int count;
	char *aws;

	count = 1;
	fd = open('test.txt', O_RDONLY);
	return_fd = get_next_line(fd, &aws);
	while (return_fd > 0)
	{
		printf("line %i: %s", count++, aws);
		free(aws);
		return_fd = get_next_line(fd, &aws);
	}
	printf("line %i: %s", count++, aws);
	free(aws);
	close(fd);
}

The return of this function is store in 'return_fd' that returns:

• 1 if found a line with \n on the end;
• 0 if found the last line of the file;
• -1 if a error is found

get_next_line_bonus

Is similar to get_next_line, but, in this function you can walk through the files simultaneously, without lose the line that you stopped read

The implementation is the same the get_next_line, with the same parameters:

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

int main()
{
	int fd1;
	int fd2;
	char *aws;

	fd1 = open('test1.txt', O_RDONLY);
	fd2 = open('test2.txt', O_RDONLY);
	get_next_line(fd1, &aws);
	printf("line 1 txt 1: %s", aws);
	free(aws);
	get_next_line(fd2, &aws);
	printf("line 1 txt 1: %s", aws);
	free(aws);
	get_next_line(fd1, &aws);
	printf("line 1 txt 1: %s", aws);
	free(aws);
	get_next_line(fd2, &aws);
	printf("line 1 txt 1: %s", aws);
	free(aws);
	close(fd);
}

Note in this example, that i call my function fisrt passing my fd1,and then calls again with fd2, in the third call of my function, the fd1 will start read again from where stopped.

Observations

• In all those examples, i use free() on 'aws' because, inside the function, is used malloc to store the line in variable.
• For this function works, must initialize the function BUFFER_SIZE on compilation moment, with the number of bytes the read()(that is inside the function get_next_line) will read.