/* 
tcpget, the poor man's netcat for TOPS-20

Send a string to a host on a port, get the response. Cobbled together
with code examples, compiles on TOPS-20 panda-dist with:

@COMPILE TCPGET.C
@LOAD TCPGET.REL
@SAVE TCPGET.EXE

Use it to get gopher(70), http(80), finger(79), etc. text content.

Usage: tcpget hostname port [string to send] [save as filename]
Examples: tcpget sdf.org 70 "/phlogs/"
          tcpget sdf.org 70 "/phlogs/" output.txt
          tcpget sdf.org 79
          tcpget sdf.org 79 "tfurrows@sdf.org"
          tcpget sdf.org 80 "GET /"

tfurrows@sdf.org, 2019, in the public domain
*/

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

/* character translations */
#ifndef  __SASC__
#define ntohcs(c) (c)
#define htoncs(c) (c)
#endif

#define TRUE 1
#define FALSE 0
#define RD_BLK_SZ 256
#define OUTB_SZ 2

int main(int argc, char *argv[]) {
   int n, i, s, port;
   char cr = 0x0D, lf = 0x0A;
   char in[RD_BLK_SZ];
   FILE *f;

   struct sockaddr_in sa;
   struct hostent *host;

   if (argc < 3) {
      printf("usage: tcpget hostname port [string to send] [save as filename]\n"
);
      exit(EXIT_FAILURE);   
   } else {
      host = gethostbyname(argv[1]);
      port = atoi(argv[2]);
   }
   
   if (host==NULL) {
       printf("tcpget: host \"%s\" not found\n",argv[1]);
       exit(EXIT_FAILURE);
   }

   memset(&sa,'\0',sizeof(sa));
   sa.sin_family = AF_INET;
   memcpy(&sa.sin_addr,host->h_addr,sizeof(sa.sin_addr));
   sa.sin_port = htons(port);

   s = socket(AF_INET, SOCK_STREAM, 0);
   if (s == -1) {
      perror("tcpget: error on socket()\n");
      exit(EXIT_FAILURE);
   }

   if (connect(s, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
      perror("tcpget: error on connect()\n");
      return(EXIT_FAILURE);
   }

   if (argc > 3) {
      write(s,argv[3],strlen(argv[3]));
   }
   if (argc == 5) {
      f = fopen(argv[4], "w");
      if (f == NULL) {
         printf("tcpget: error opening output file.\n");
         exit(EXIT_FAILURE);
      }      
   }
      
   write(s,&cr,1);
   write(s,&lf,1);

   while (n=read(s,in,RD_BLK_SZ)) {
      for (i=0; i<n ; i++) {
         if (in[i]==cr) continue;
         if (f != NULL && argc == 5) {
            fprintf(f, "%c", ntohcs(in[i]));
         } else {
            putchar(ntohcs(in[i]));
         }
      }
   }

   if (f != NULL && argc == 5) {
      fclose(f);
   }

   close(s);
}