BSD 4_2 development

[unix-history] / usr / src / ucb / talk / get_names.c

/* $Header: get_names.c 1.2 83/03/26 14:35:54 moore Exp $ */

#include "talk.h"
#include "ctl.h"

char *getlogin(), *ttyname(), *rindex();

extern CTL_MSG msg;

/*
* Determine the local and remote user, tty, and machines
*/

struct hostent *gethostbyname();

get_names(argc, argv)
int argc;
char *argv[];
{
   char hostname[HOST_NAME_LENGTH];
   char *his_name;
   char *my_name;
   char *my_machine_name;
   char *his_machine_name;
   char *my_tty;
   char *his_tty;
   char *ptr;
   int name_length;

   if (argc < 2 ) {
       printf("Usage:  talk user [ttyname]\n");
       exit(-1);
   }
   if ( !isatty(0) ) {
       printf("Standard input must be a tty, not a pipe or a file\n");
       exit(-1);
   }

   my_name = getlogin();
   if (my_name == NULL) {
       printf("You don't exist. Go away.\n");
       exit(-1);
   }

   name_length = HOST_NAME_LENGTH;
   gethostname(hostname, &name_length);
   my_machine_name = hostname;

   my_tty = rindex(ttyname(0), '/') + 1;

       /* check for, and strip out, the machine name 
           of the target */

   for (ptr = argv[1]; *ptr != '\0' &&
                        *ptr != '@' &&
                        *ptr != ':' &&
                        *ptr != '!' &&
                        *ptr != '.'     ; ptr++) {
   }

   if (*ptr == '\0') {

           /* this is a local to local talk */

       his_name = argv[1];
       his_machine_name = my_machine_name;

   } else {

       if (*ptr == '@') {
               /* user@host */
           his_name = argv[1];
           his_machine_name = ptr + 1;
       } else {
               /* host.user or host!user or host:user */
           his_name = ptr + 1;
           his_machine_name = argv[1];
       }
       *ptr = '\0';
   }


   if (argc > 2) {
       his_tty = argv[2];      /* tty name is arg 2 */
   } else {
       his_tty = (char *) 0;
   }

   get_addrs(my_machine_name, his_machine_name);

       /* Load these useful values into the standard message header */

   msg.id_num = 0;

   strncpy(msg.l_name, my_name, NAME_SIZE);
   msg.l_name[NAME_SIZE - 1] = '\0';

   strncpy(msg.r_name, his_name, NAME_SIZE);
   msg.r_name[NAME_SIZE - 1] = '\0';

   strncpy(msg.r_tty, his_tty, TTY_SIZE);
   msg.r_tty[TTY_SIZE - 1] = '\0';
}