#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>

int main()
{
    int fd[2], result;
    size_t size;
    char resstring[14];

    if(pipe(fd) < 0)
         {
        printf("Can\'t create pipe\n");
        exit(-1);
         }

    result = fork();
    if(result < 0)
        {
        printf("Can\'t fork child\n");
        exit(-1);
         }
    else if (result > 0)
         {
        /* процесс-предок*/
        close(fd[0]);
    printf("Father is going to send a letter to his beloved son...\n");
        size = write(fd[1], "Hello, world!", 14);
        if(size != 14)
            {
            printf("Can\'t write all string\n");
            exit(-1);
            }
        
        close(fd[1]);
    printf("Father wants his letter to reach the final destination.\n");
        printf("Parent exit\n");
         }
    else {
        /* процесс - потомок*/
        close(fd[1]);
    printf("Son decides to check his inbox...\n");    
        size = read(fd[0], resstring, 14);
        if(size < 0)
            {
            printf("Can\'t read string\n");
            exit(-1);
            }
    printf("Son has just recieved a nice letter from his father.\n");
    printf("Here it is:\n");
        printf("\"%s\"\n",resstring);    
        close(fd[0]);
         }    
    getchar();
    return 0;
}