server.c

在两台计算机间用并行打印口通信的TURBO C程序

/* receiver for parallel port file transfer */

#include <stdio.h>
#include <io.h>
#include <fcntl.h>
#include <stat.h>
#include <ctype.h>
#include <dir.h>
#include <dos.h>
#include <conio.h>
#include <string.h>
#include <stdlib.h>
#include "pport.h"

int receive_file(int handle, long size);

#define R_BLOCK   2048           /* must be same as T_BLOCK in client */
#define DIR_BUF_SIZE 30000       /* must be same in client and < 32K */

char buffer[R_BLOCK];
char dir_buffer[DIR_BUF_SIZE];

#define MAX_WAIT  1200

main()
{
   int i, j, k, count, h;
   long size, free, total;
   char name[121], *endptr, b[131], *dn, *p, *limit;
   struct ffblk fb;
   struct dfree df;


   printf("\n\n\n                            File transfer server\n\n");
   
   pp_initialize(0);
   
   while(1)
   {  j = pp_read_data_block(&count, buffer);

      if (j == CHAR1_TIMEOUT)
      {  if (kbhit())
         {  k = getch();
            if (k == 'q' || k == 'Q')
            {  pp_initialize(0);
               exit(0);
            }
         }
         continue;
      }
      if (j != OK) barfr(j);
      
      buffer[count] = 0;               /* insert a nul */
      
      if (!strnicmp(buffer, "quit", 4))
      {  printf("QUIT command received\n");
         pp_initialize(0);
         exit(0);
      }

      else if(!strnicmp(buffer, "HI", 2))
      {  pp_delay();                      /* don't overrun client! */
         pp_send("HI");
      }
      
      else if(!strnicmp(buffer, "PWD", 3))   /* return current directory */
      {  getcwd(b, 121);
         pp_send(b);
      }
      
      else if(!strnicmp(buffer, "CD", 2))    /* change dir */
      {  dn = buffer + 3;                    /* CD is followed by blank */
         if (dn[1] == ':') 
         {  if (strlen(dn) == 2) strcat(dn, "\\");
            j = toupper(dn[0]) - 'A';
            k = setdisk(j);
            if (j >= k)
            {  pp_send("BAD DISK");
               continue;
            }
         }
         k = chdir(dn);
         if (k != 0)
         {  pp_send("BAD DIRECTORY");
            continue;
         }
         pp_send("OK");
      }

      else if(!strnicmp(buffer, "DIR", 3))    /* display dir */
      {  dn = buffer + 4;                     /* DIR is followed by blank */
         j = strlen(dn);
         if (j == 0 || dn[j-1] == ':' || dn[j-1] == '\\') strcat(dn, "*.*");

         p = dir_buffer;
         limit = dir_buffer + DIR_BUF_SIZE - 100;
         k = 0;
         total = 0;
         j = findfirst(dn, &fb, FA_DIREC);
         if (j == 0) do
         {  if (fb.ff_attrib == FA_DIREC)
               j = sprintf(p, "%-12s          [Dir]\n", fb.ff_name);
            else
            {  j = sprintf(p, "%-12s   %8ld   %2d/%02d/%2d\n",
                  fb.ff_name, fb.ff_fsize, (fb.ff_fdate >> 5) & 0xf, 
                     fb.ff_fdate & 0x1f, (fb.ff_fdate >> 9) + 80);
               total += fb.ff_fsize;
            }
            p += j;
            k++;
            if (p > limit)
            {  p = stpcpy(p, "Directory too big\n");
               break;
            }
         } while (0 == findnext(&fb));
         if(dn[1] == ':') j = toupper(dn[0]) - 'A' + 1;
         else j = 0;
         getdfree(j, &df);
         sprintf(p, "... %d files - %ld bytes total, %ld bytes free ...\n\n",
                   k, total, (long)df.df_avail * df.df_bsec * df.df_sclus);
         pp_send(dir_buffer);
      }



      else if(!strnicmp(buffer, "MD", 2))    /* make dir */
      {  dn = buffer + 3;                    /* MD is followed by blank */
         k = mkdir(dn);
         if (k != 0)
         {  pp_send("CAN\'T CREATE DIRECTORY");
            continue;
         }
         pp_send("OK");
      }

      else if(!strnicmp(buffer, "PUT", 3))
      {  size = strtol(buffer+3, &endptr, 10);
         buffer[count] = 0;
         strcpy(name, endptr + 1);
         h = open(name, O_RDONLY);
         if (h >= 0)             /* file exists */
         {  close(h);
            sprintf(b, "%s EXISTS", name);
            pp_send(b);
         }
         else
         {  h = open(name, O_WRONLY | O_BINARY | O_CREAT, S_IREAD | S_IWRITE);
            if (h < 0) pp_send("CAN\'T OPEN");
            else
            {  pp_send("SEND");
               receive_file(h, size);
               close(h);
               printf("Received: %s\n", name);
            }
         }
      }
      
      else        /* unknown command */
      {  buffer[8] = 0;
         printf("Unrecognized command >%s<\n", buffer);
      }
   }
}





int receive_file(int handle, long size)
{  int i, j, n;
   
   while(size > 0)
   {  for (i=0;  i<MAX_WAIT;  i++)
      {  j = pp_read_data_block(&n, buffer);
         if (j != CHAR1_TIMEOUT) break;
      }
      if (j == CSUM_FAIL || j == COUNT_FAIL)
      {  printf("Repeat\n");
         pp_send("REPEAT");
         continue;
      }
      else if (j == OK)
      {  write(handle, buffer, n);
         size -= n;
         pp_send("OK");
      }
      else barfr(j);
   }
}






pp_send(char *s)           /* send string, re-tryng on char1 timeouts */
{
   int j;
   
   while(1)
   {  j = pp_send_data_block(strlen(s), s);
      if (j == OK) return;
      if (j != CHAR1_TIMEOUT) barft(j);
   }
}


barfr(int j)                /* report death */
{  int i;

   printf("Data receive failed with return code %d\n", j);
   for(i=0;  i<8;  i++) printf("  %02x", buffer[i]);
   printf("\n");
   pp_initialize(0);
   exit(99);
}


barft(int j)
{
   printf("Transmission failed with error code %d\n", j);
   pp_initialize(0);
   exit(99);
}