#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <string.h>

#define UNIX_PATH_MAX    108

int main(void)
{
    struct sockaddr_un address;
    int  socket_fd, nbytes;
    char buffer[256];

    socket_fd = socket(PF_UNIX, SOCK_STREAM, 0);
    if (socket_fd < 0)
    {
        printf("socket() failed\n");
        return 1;
    }

    /* start with a clean address structure */
    memset(&address, 0, sizeof(struct sockaddr_un));
 
    address.sun_family = AF_UNIX;
    snprintf(address.sun_path, UNIX_PATH_MAX, "./demo_socket");

    if (connect(socket_fd, (struct sockaddr *)&address,  
                sizeof(struct sockaddr_un)) != 0)
    {
        printf("connect() failed\n");
        return 1;
    }

    nbytes = snprintf(buffer, 256, "hello from a client");
    write(socket_fd, buffer, nbytes);
 
    nbytes = read(socket_fd, buffer, 256);
    buffer[nbytes] = 0;

    printf("MESSAGE FROM SERVER: %s\n", buffer);

    close(socket_fd);

    return 0;
}