uts.c

来自「稀疏矩阵、链表、图、队列、二叉树、多叉树、排序、遗传算法等的实现」· C语言 代码 · 共 193 行

/*  uts.c - UNIX TCP Server Code
*
*
*  Copyright (C) 1999   Chad Dixon
*                       Macmillan Computer Publishing
*
*  This program is free software; you can redistribute it
*  and/or modify it under the terms of the GNU General
*  Public License as published by the Free Software
*  Foundation; either version 2 of the License, or
*  (at your option) any later version.
*
*  This program is distributed in the hope that it will
*  be useful, but WITHOUT ANY WARRANTY; without even the
*  implied warranty of MERCHANTABILITY or FITNESS FOR A
*  PARTICULAR PURPOSE.  See the GNU General Public License
*  for more details.
*
*  You should have received a copy of the GNU General
*  Public License along with this program; if not, write
*  to the Free Software Foundation, Inc., 675 Mass Ave,
*  Cambridge, MA 02139, USA.
*
*  Chad Dixon may be contacted at:
*     http://www.loopy.org
*
*/


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/select.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>


#define DEFAULT_FILE_NAME "sales.dat"

volatile sig_atomic_t done;


void inthandler(int Sig)
{
 done = 1;
}

int CheckForData(int sockfd)
 {
  struct timeval tv;
  fd_set read_fd;
  tv.tv_sec=0;
  tv.tv_usec=0;
  FD_ZERO(&read_fd);
  FD_SET(sockfd, &read_fd);
  if(select(sockfd+1, &read_fd,NULL, NULL, &tv)== -1)
  {
   return 0;
  }
   if(FD_ISSET(sockfd, &read_fd))
   {
    return 1; 
   }
 return 0;
}          


int main(int argc, char **argv)
 { 
  int sockfd=0;  
  int new_fd=0;  
  struct sockaddr_in my_addr; 
  struct sockaddr_in their_addr; 
  socklen_t sin_size=0;
  char data[255]={0};
  char *endp;

  FILE *fp;
  char Filename[FILENAME_MAX] = DEFAULT_FILE_NAME;
  unsigned long currenttotal = 0;
  unsigned long  newtotal = 0;
  if(argc < 2)
  {
    printf("No file specified. Using \"%s\"\n", DEFAULT_FILE_NAME);
  }
  else
  {
    strcpy(Filename, argv[1]);
  }

  fp = fopen(Filename, "r");
  if(fp != NULL)
  {
    if(NULL != fgets(data, sizeof data, fp))
    {
      currenttotal = strtoul(data, &endp, 10);
    }

    fclose(fp);
  }
  else
  {
    printf("Couldn't read file %s\n", Filename);
  }

  if(signal(SIGINT, SIG_IGN) != SIG_IGN)
   {
    signal(SIGINT, inthandler);
   }

  if(signal(SIGTERM, SIG_IGN) != SIG_IGN)
   {
    signal(SIGTERM, inthandler); 
   }

  my_addr.sin_family = AF_INET;   
  my_addr.sin_addr.s_addr = INADDR_ANY; 
  my_addr.sin_port = htons(1091); 

  memset(my_addr.sin_zero, 0,sizeof my_addr.sin_zero);  

  if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) 
   {
    printf("Unexpected error on socket().\n");
    return EXIT_FAILURE; 
   }

  if (bind(sockfd,(struct sockaddr *)&my_addr, sizeof(struct sockaddr))== -1) 
  {
   printf("Unexpected error on bind()\n");
   return EXIT_FAILURE;
  }

  if (listen(sockfd, 4) == -1) 
   {
    printf("Unexpected error on listen()\n");
    shutdown(sockfd,2);
    return EXIT_FAILURE; 
   }



   while(!done) 
    {  
     if(0 != CheckForData(sockfd))
     {
     sin_size = sizeof(struct sockaddr_in);
     if ((new_fd = accept(sockfd,(struct sockaddr *) &their_addr, &sin_size)) == -1) 
      {
       printf("Unexpected error on accept()\n");
       continue;
      }
      
     memset(data, 0, sizeof data);

     if (recv(new_fd, data, sizeof data, 0) == -1) 
      {
       printf("Unexpected error on recv()\n");
      }        
      else
      {
        newtotal += strtoul(data, &endp, 10);
        printf("Received data: %s\n", data);
      }
     sprintf(data, "%lu\n", currenttotal);
     if (send(new_fd, data, sizeof data, 0) == -1) 
      {
       printf("Unexpected error on send()\n");
      }        
      shutdown(new_fd, 2);
    }
  }
  shutdown(sockfd,2);
  printf("User requested program to halt.\n");
  fp = fopen(Filename, "w");
  if(fp != NULL)
  {
    fprintf(fp, "%lu\n", newtotal);
    fclose(fp);
  }
  else
  {
    printf("Couldn't write total %lu to file %s\n", newtotal, Filename);
  }
  
  return EXIT_SUCCESS; 
}