Connection many client fifo to one server fifo

问题

have to write two programs (a client and a server) which will do chatting with each other using FIFOs (to pass message from one process to another). The server process creates a SERVER_FIFO to receive client connections only. The server maintains the list of online clients. Each client creates its own CLIENT_FIFO to receive commands from server to be executed at client using system() system call. You can use getpid() system call to retrieve client’s process id to be concatenated in the CLIENT_FIFO name.

I only to create 2 fifo that communicate with each other

SERVER

// C program to implement one side of FIFO 
// This side writes first, then reads 
#include <stdio.h> 
#include <string.h> 
#include <fcntl.h> 
#include <sys/stat.h> 
#include <sys/types.h> 
#include <unistd.h> 

int main() 
{ 
    int fd; 

    char * myfifo = "/tmp/myfifo"; 

    mkfifo(myfifo, 0666); 

    char arr1[80], arr2[80]; 
    while (1) 
    { 

        fd = open(myfifo, O_WRONLY); 

        fgets(arr2, 80, stdin); 

        write(fd, arr2, strlen(arr2)+1); 
        close(fd); 

        // Open FIFO for Read only 
        fd = open(myfifo, O_RDONLY); 

        // Read from FIFO 
        read(fd, arr1, sizeof(arr1)); 

        // Print the read message 
        printf("User2: %s\n", arr1); 
        close(fd); 
    } 
    return 0; 
} 

==================================================================

CLIENT

// C program to implement one side of FIFO 
// This side reads first, then reads 
#include <stdio.h> 
#include <string.h> 
#include <fcntl.h> 
#include <sys/stat.h> 
#include <sys/types.h> 
#include <unistd.h> 

int main() 
{ 
    int fd1; 

    // FIFO file path 
    char * myfifo = "/tmp/myfifo"; 

    mkfifo(myfifo, 0666); 

    char str1[80], str2[80]; 
    while (1) 
    { 
        // First open in read only and read 
        fd1 = open(myfifo,O_RDONLY); 
        read(fd1, str1, 80); 

        // Print the read string and close 
        printf("User1: %s\n", str1); 
        close(fd1); 


        fd1 = open(myfifo,O_WRONLY); 
        fgets(str2, 80, stdin); 
        write(fd1, str2, strlen(str2)+1); 
        close(fd1); 
    } 
    return 0; 
} 

来源：https://stackoverflow.com/questions/58812591/connection-many-client-fifo-to-one-server-fifo