client.c.txt

unix program of tcp ip client server for network sockets

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/time.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/time.h>
#include <signal.h>
#include <wait.h>
#include <fcntl.h>
#include <sys/stat.h>

#define SRVRPORT 3000
#define BUFSIZE 4096

void reaper(int sig)
{
        int status;
        while(wait3(&status, WNOHANG, (struct rusage *)0) >= 0); //wait3 is used to cleanup all child process as opposed to wait - which cleans up only one child.
}


int main(int argc, char **argv)
{

        int sockd, c,p,q,conncount,clinst,n=0;
        struct sockaddr_in sin;
        char buf[BUFSIZE];
        char *filename,*servername;
        pid_t pid=1;
        struct timeval tval;
        double start_ttime, end_ttime;
        struct hostent *hostp;

        if(argc != 5) {
                printf("Usage: %s < filename>  <servername > <client instances> <connections> \n", argv[0]);
        }

        switch(argc)
        {
                case 5:
                        conncount = atoi(argv[4]);
                        clinst = atoi(argv[3]);
                        servername = argv[2];
                        filename = argv[1];
                        break;

                case 4:
                        clinst = atoi(argv[3]);
                        servername = argv[2];
                        filename = argv[1];
                        conncount = 5;
                        break;

                case 3:
                        servername = argv[2];
                        filename = argv[1];
                        clinst = 5;
                        conncount = 5;
                        break;

                case 2:
                        filename = argv[1];
                        servername = "localhost";
                        clinst = 5;
                        conncount = 5;
                        break;
                default:
                        printf("Usage: %s < filename>  <servername > <client instances> <connections> \n", argv[0]);
                        exit(0);
        }

strcpy(servername, argv[2]);
 printf("File that is being read by the client is %s\n",filename);
 printf("Number of instances in the client is %d\n",clinst);
 printf("Number of connections per instance in this client is %d\n",conncount);
gettimeofday(&tval,NULL);
start_ttime = tval.tv_sec + tval.tv_usec/100000.0;
for (p = 0; p <= clinst-1; p++,n=0)
{
     if(pid !=0){

     if((pid = fork()) == 0)
   {

          /* Starting time */
   for (q = 1; q <= conncount; q++)
    {
        sockd = socket(AF_INET,SOCK_STREAM,0);
        if(sockd <= 0) {
                perror("socket");
                exit(-1);
        }
        sin.sin_family = AF_INET;
        sin.sin_port = htons(SRVRPORT);
        sin.sin_addr.s_addr = INADDR_ANY;

        hostp = gethostbyname(servername);
        if(hostp == (struct hostent *)NULL)
        {
                printf("HOST NOT FOUND --> ");
                /* h_errno is usually defined in netdb.h */
                printf("---This is a client program---\n");
                printf("Command usage: %s <server name or IP>\n", argv[0]);
                close(sockd);
                exit(-1);
        }

        memcpy(&sin.sin_addr, hostp->h_addr, sizeof(sin.sin_addr));

        c = connect(sockd, (struct sockaddr *)&sin, sizeof(sin));
        if( c == -1) {
                perror("connect");
                exit(-1);
        }
        int i;

        i = write(sockd, filename, strlen(filename));
        int k,totalsize = 0;
        while ((k = read(sockd,buf,sizeof(buf))) > 0 ) {
                 printf("Number of bytes read %d\n", k);
                 totalsize += k;
        }
        printf("Total number of bytes read for %d instance and %d is%d\n", p+1, q,totalsize);
        if (k < 0) {
                perror("read");
                exit(0);
        }

        //close(c);
     }
 //     gettimeofday(&tval,NULL);
   //     end_time = tval.tv_sec + tval.tv_usec/100000.0;
     //   n=n + abs((end_time-start_time)*1000);
        /* Printing the output : Time taken in ms */
      }
  }
}
gettimeofday(&tval,NULL);
end_ttime = tval.tv_sec + tval.tv_usec/100000.0;
printf("Total time for %d instance and %d connection is %d\n",p,conncount,abs((end_ttime-start_ttime)*1000));
reaper(-1);
exit(1);
//return 0;
}