Get_next_line - 42 School Project

About · Usage

About

The 42 school's get_next_line project is where we learn to read from a file descriptor, as well as the use of static variables.

This function returns a single line from a given file descriptor. If called in a loop, get_next_line returns the entire contents of a file, line by line until it reaches the end of the file. It can be compiled specifying any buffer size.

Usage

This function is not a stand-alone program, its files must be included and compiled within another project.

Example main.c:

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

	fd = open("test.txt", O_RDONLY);
	if (fd == -1)
	{
		perror("Erreur d'ouverture du fichier");
		return (1);
	}
	while ((line = get_next_line(fd)) != NULL)
	{
		printf("Ligne lue : %s", line);
		free(line);
	}
	close(fd);
	return (0);
}

Compilation:

gcc -Wall -Wextra -Werror get_next_line.c get_next_line_utils.c -o get_next_line

BUFFER_SIZE can be specified at compilation to override the default BUFFER_SIZE:

gcc -Wall -Werror -Wextra -D BUFFER_SIZE=42 get_next_line.c get_next_line_utils.c -o get_next_line

Execution:

./get_next_line [file]

Output should show the entire contents of the given file.

Execution with stdin:

./a.out /dev/tty

Program will wait for input, then once the enter key is pressed, print out the input as well as get_next_line's output. The process can be killed with ctrl-c.