ronanboiteau / get_next_line

{EPITECH.} C function that reads line per line from a file descriptor.

get_next_line()

{EPITECH.} first year project.

C function that reads from a filedescriptor line per line, each time the function is called.

Prototype

char *get_next_line(int const fd);

How to use get_next_line()?

Editing the header file

• get_next_line() retrieves lines using the read(2) syscall.

• The READ_SIZE macro located inside the get_next_line.h header file represents the number of bytes that are read each time read(2) is called.

• You can edit this macro to optimized the number of calls to read(2).

#  define READ_SIZE (32)

If you don't know what to do, simply keep the default value.

Including the header

Include get_next_line()'s header file inside your C source file:

#include "get_next_line.h"

Calling the function

• When calling get_next_line(), feed it a filedescriptor as a type int argument.
• Each time you call get_next_line(), the function allocates & returns a char *.
• The first time you call get_next_line(), the char * returned contains the first line found when reading from the filedescriptor you fed to the function.
• After the first call, each call to get_next_line() with the same filedescriptor will return the next line found.
• When there is no more line to read, get_next_line() returns NULL.
• If a fatal error occurs (malloc(3) or read(2) failure), get_next_line() also returns NULL.

Here is an example that reads and prints all the lines from stdin:

char *line;
while ((line = get_next_line(0)) != NULL)
      printf("Next line -> %s", line);