Condor 2009 Winter

Jan 29, 2009:

Fedora 10 Uses Condor 7.2 so we should switch from 7.0.5.

• git clone git://git.et.redhat.com/mrg-grid.git
• cd mrg-grid
• git-checkout -b jas origin/V7.2.0-condor_config.generic
• cd src
• ./build_init
• ./configure --disable-full-port --enable-proper --disable-gcc-version-check --disable-glibc-version-check
• make
• make release

Feb 8, 2009:

• yum install seamonkey //used to edit html to get the C program
• yum groupinstall "Development Libraries"
• yum groupinstall "Development Tools"
• server.c

1. include <error.h>
2. include <errno.h>
3. include <netdb.h>
4. include <stdio.h>
5. include <stdlib.h>
6. include <string.h>
7. include <unistd.h>
8. include <arpa/inet.h>
9. include <netinet/in.h>
10. include <sys/poll.h>
11. include <sys/poll.h>

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

 struct servent *s = getservbyname ("echo", "tcp");
 if (s == NULL)
   error (EXIT_FAILURE, errno, "getservent");
 struct pollfd fds[1];

 int nfds = 0;
 fds[nfds].fd = socket (AF_INET, SOCK_STREAM, 0);

 if (fds[nfds].fd == -1)
   error (EXIT_FAILURE, errno, "socket");
 fds[nfds].events = POLLIN;
 int opt = 1;
 setsockopt (fds[nfds].fd, SOL_SOCKET, SO_REUSEADDR,
             opt, sizeof (opt));
 struct sockaddr_in sin;
 sin.sin_family = AF_INET;

 sin.sin_port = s->s_port;
 sin.sin_addr.s_addr = INADDR_ANY;
 if (bind (fds[nfds].fd,
           &sin, sizeof (sin)) != 0)

   error (EXIT_FAILURE, errno, "bind");

 if (listen (fds[nfds].fd, SOMAXCONN) != 0)
   error (EXIT_FAILURE, errno, "listen");
 ++nfds;
 int i = 0;

 while (1)
   {
     int n = poll (fds, nfds, -1);
     if (n > 0)

       if (fds[i].revents & POLLIN)
         {
           struct sockaddr_in rem;
           socklen_t remlen = sizeof (rem);
           int fd = accept (fds[i].fd, (struct sockaddr *) &rem, &remlen);
           if (fd != -1)
             {
               struct hostent *h = gethostbyaddr (&rem.sin_addr,
                                                  sizeof (rem.sin_addr),
                                                  rem.sin_family);
               char *buf1 = h ? h->h_name : "???";
               char *buf2 = inet_ntoa (rem.sin_addr);

               printf ("connection from %s (%s)\n", buf1, buf2);
               char buf[1000];
               ssize_t l = read (fd, buf, sizeof (buf));
               buf[0]='J';
               write (fd, buf, l);
               close (fd);
             }
         }
   }

}

• cc server.c -o server
• client.c

1. include <errno.h>
2. include <error.h>
3. include <netdb.h>
4. include <stdio.h>
5. include <stdlib.h>

1. include <unistd.h>
2. include <netinet/in.h>
3. include <sys/socket.h>

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

 int result = 0;
 struct hostent *h = gethostbyname (argv[1]);
 if (h == NULL)
   error (EXIT_FAILURE, errno, "gethostbyname");
 struct servent *s = getservbyname ("echo", "tcp");
 if (s == NULL)
   error (EXIT_FAILURE, errno, "getservbyname");
 struct in_addr **addrs = (struct in_addr **) h->h_addr_list;
 while (*addrs != NULL)
   {
     int sock = socket (PF_INET, SOCK_STREAM, 0);

     if (sock != -1)
       {
         struct sockaddr_in sin;
         sin.sin_family = AF_INET;
         sin.sin_port = s->s_port;
         sin.sin_addr = **addrs;
         if (connect (sock,
                      (struct sockaddr *) &sin, sizeof (sin)) == 0)
           {
             char *line = NULL;
             size_t len = 0;
             ssize_t n = getline (&line, &len, stdin);
             write (sock, line, n);
             n = read (sock, line, len);
             write (STDOUT_FILENO, line, n);
             close (sock);
             goto out;
           }
         close (sock);
       }
     ++addrs;
   }
 error (0, 0, "cannot contact %s", argv[1]);
 result = 1;
out:

 return result;

}

• cc client.c -o client
• ./server
• ./client localhost //open another terminal to run it, then type a little word to test. OK