Pipe

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

#define BUFF_SIZE 20

int main(int argc, char **argv)
{
    int fd[2];
    int pid;
    int pip_id;
    char buff[BUFF_SIZE];
    char buff_size[BUFF_SIZE] = "hello!\n";

    pip_id = pipe(fd);                                                        //Create Pipe
    if (pip_id < 0)
        return -1;

    if ((pid = fork()) < 0) {                                              // Create process
        perror("Create pid failed");
        return -1;
    }

    if (pid == 0) {                                                      // Child process

        while (1) {
            write(fd[1], buff_size, sizeof(buff_size));

            sleep(1);
        }

    } else {
        while (1) {
            read(fd[0], &buff, sizeof(buff));                   // Father process
            sleep(1);
            printf("buff = %s\n", buff);


        }
    }

    return 0;
}
 
                                            _________________
   read(fd[0])  <------------   |________pipe______| <------------- write(fd[1])