scripts/training/parallelize/sentclient.c

/* Copyright (c) 2001 by David Chiang. All rights reserved.*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>
#include <string.h>

#include "sentserver.h"

int main (int argc, char *argv[]) {
  int sock, port;
  char *s, *key;
  struct hostent *hp;
  struct sockaddr_in server;
  int errors = 0;

  if (argc < 3) {
    fprintf(stderr, "Usage: sentclient host[:port[:key]] command [args ...]\n");
    exit(1);
  }

  s = strchr(argv[1], ':');
  key = NULL;

  if (s == NULL) {
    port = DEFAULT_PORT;
  } else {
    *s = '\0';
    s+=1;
	/* dumb hack */
	key = strchr(s, ':');
	if (key != NULL){
		*key = '\0';
		key += 1;
	}
    port = atoi(s);
  }

  sock = socket(AF_INET, SOCK_STREAM, 0);

  hp = gethostbyname(argv[1]);
  if (hp == NULL) {
    fprintf(stderr, "unknown host %s\n", argv[1]);
    exit(1);
  }

  bzero((char *)&server, sizeof(server));
  bcopy(hp->h_addr, (char *)&server.sin_addr, hp->h_length);
  server.sin_family = hp->h_addrtype;
  server.sin_port = htons(port);

  fprintf(stderr,"connecting to %s:%d\n", argv[1], port);
  fflush(stderr);

  while (connect(sock, (struct sockaddr *)&server, sizeof(server)) < 0) {
    perror("connect()");
    sleep(1);
    errors++;
    if (errors > 5)
      exit(1);
  }

  close(0);
  close(1);
  dup2(sock, 0);
  dup2(sock, 1);

  if (key != NULL){
	write(1, key, strlen(key));
	write(1, "\n", 1);
  }

  execvp(argv[2], argv+2);
  return 0;
}