#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>

const char *path = "/tmp/fifo-server-432423";
char path_pid_1[500];
char path_pid_2[500];
const char *suf_1 = "-1-";
const char *suf_2 = "-2-";

void handle_error(char *txt)
{
    perror(txt);
    exit(1);
}

int main()
{
    int m_w, m_r;
    int db_w, db_r;
    char pid_str[20];
    int m_fifo;
    int pid = getpid();

    strcpy(path_pid_1, path);
    strcpy(path_pid_2, path);
    strcpy(path_pid_1, strcat(path_pid_1, suf_1));
    strcpy(path_pid_2, strcat(path_pid_2, suf_2));
    sprintf(pid_str, "%d", pid);
    strcpy(path_pid_1, strcat(path_pid_1, pid_str));
    strcpy(path_pid_2, strcat(path_pid_2, pid_str));

    if (access(path_pid_1, F_OK) == 0)
        unlink(path_pid_1);
    if (access(path_pid_2, F_OK) == 0)
        unlink(path_pid_2);

    if ((m_fifo = mkfifo(path_pid_1, 0600)) == -1)
        handle_error("pid1 mkfifo");
    if ((m_fifo = mkfifo(path_pid_2, 0600)) == -1)
        handle_error("pid2 mkfifo");
    if ((m_w = open(path, O_WRONLY)) == -1)
        handle_error("main open");

    printf("writing pid\n");
    write(m_w, (void *)&pid, sizeof(pid_t));

    if ((db_w = open(path_pid_1, O_WRONLY)) == -1)
        handle_error("db_w open");
    if ((db_r = open(path_pid_2, O_RDONLY)) == -1)
        handle_error("db_r open");

    double db = 2.21212;
    printf("writing db\n");
    write(db_w, (void *)&db, sizeof(double));
    close(db_w);
    printf("reading db\n");
    read(db_r, (void *)&db, sizeof(double));
    close(db_r);
    printf("%f\n", db);

    return 0;
}