server.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <fcntl.h>
int main()
{
    int s_sock, c_sock;
    s_sock = socket(AF_INET, SOCK_STREAM, 0);
    struct sockaddr_in server, other;
    memset(&server, 0, sizeof(server));
    memset(&other, 0, sizeof(other));
    server.sin_family = AF_INET;
    server.sin_port = htons(9009);
    server.sin_addr.s_addr = INADDR_ANY;
    socklen_t add;

    if (bind(s_sock, (struct sockaddr *)&server, sizeof(server)) == -1)
    {
        printf("Binding failed\n");
        return 0;
    }
    printf("\tServer Up\n Go back n (n=3) used to send 10 messages \n\n");
    listen(s_sock, 10);
    add = sizeof(other);
    c_sock = accept(s_sock, (struct sockaddr *)&other, &add);
    time_t t1, t2;
    char msg[50] = "server message :";
    char buff[50];
    int flag = 0;

    fd_set set1, set2, set3;
    struct timeval timeout1, timeout2, timeout3;
    int rv1, rv2, rv3;

    int i = -1;
qq:
    i = i + 1;
    bzero(buff, sizeof(buff));
    char buff2[60];
    bzero(buff2, sizeof(buff2));
    strcpy(buff2, "server message :");
    buff2[strlen(buff2)] = i + '0';
    buff2[strlen(buff2)] = '\0';
    printf("Message sent to client :%s \n", buff2);
    write(c_sock, buff2, sizeof(buff2));
    usleep(1000);
    i = i + 1;
    bzero(buff2, sizeof(buff2));
    strcpy(buff2, msg);
    buff2[strlen(msg)] = i + '0';
    printf("Message sent to client :%s \n", buff2);
    write(c_sock, buff2, sizeof(buff2));
    i = i + 1;
    usleep(1000);
qqq:
    bzero(buff2, sizeof(buff2));
    strcpy(buff2, msg);
    buff2[strlen(msg)] = i + '0';
    printf("Message sent to client :%s \n", buff2);
    write(c_sock, buff2, sizeof(buff2));
    FD_ZERO(&set1);
    FD_SET(c_sock, &set1);
    timeout1.tv_sec = 2;
    timeout1.tv_usec = 0;

    rv1 = select(c_sock + 1, &set1, NULL, NULL, &timeout1);
    if (rv1 == -1)
        perror("select error ");
    else if (rv1 == 0)
    {
        printf("Going back from %d:timeout \n", i);
        i = i - 3;
        goto qq;
    }
    else
    {
        read(c_sock, buff, sizeof(buff));
        printf("Message from Client: %s\n", buff);
        i++;
        if (i <= 9)
            goto qqq;
    }
qq2:
    FD_ZERO(&set2);
    FD_SET(c_sock, &set2);
    timeout2.tv_sec = 3;
    timeout2.tv_usec = 0;
    rv2 = select(c_sock + 1, &set2, NULL, NULL, &timeout2);
    if (rv2 == -1)
        perror("select error "); // an error accured
    else if (rv2 == 0)
    {
        printf("Going back from %d:timeout on last 2\n", i - 1);
        i = i - 2;
        bzero(buff2, sizeof(buff2));
        strcpy(buff2, msg);
        buff2[strlen(buff2)] = i + '0';
        write(c_sock, buff2, sizeof(buff2));
        usleep(1000);
        bzero(buff2, sizeof(buff2));
        i++;
        strcpy(buff2, msg);
        buff2[strlen(buff2)] = i + '0';
        write(c_sock, buff2, sizeof(buff2));
        goto qq2;
    } // a timeout occured
    else
    {
        read(c_sock, buff, sizeof(buff));
        printf("Message from Client: %s\n", buff);
        bzero(buff, sizeof(buff));
        read(c_sock, buff, sizeof(buff));
        printf("Message from Client: %s\n", buff);
    }

    //}

    close(c_sock);
    close(s_sock);
    return 0;
}