4.3BSD beta release manual page

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

#ifndef lint
static char sccsid[] = "@(#)get_names.c 1.2 (Berkeley) %G%";
#endif

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

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

extern CTL_MSG msg;

struct hostent *gethostbyname();

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

       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);
       }
       gethostname(hostname, sizeof (hostname));
       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 = "";
       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';
}