usr/src/ucb/talk/get_names.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char sccsid[] = "@(#)get_names.c 5.5 (Berkeley) 6/29/88";
#endif /* not lint */

#include "talk.h"
#include <sys/param.h>
#include <protocols/talkd.h>
#include <pwd.h>

char    *getlogin();
char    *ttyname();
char    *rindex();
extern  CTL_MSG msg;

/*
 * Determine the local and remote user, tty, and machines
 */
get_names(argc, argv)
        int argc;
        char *argv[];
{
        char hostname[MAXHOSTNAMELEN];
        char *his_name, *my_name;
        char *my_machine_name, *his_machine_name;
        char *my_tty, *his_tty;
        register char *cp;

        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);
        }
        if ((my_name = getlogin()) == NULL) {
                struct passwd *pw;

                if ((pw = getpwuid(getuid())) == NULL) {
                        printf("You don't exist. Go away.\n");
                        exit(-1);
                }
                my_name = pw->pw_name;
        }
        gethostname(hostname, sizeof (hostname));
        my_machine_name = hostname;
        /* check for, and strip out, the machine name of the target */
        for (cp = argv[1]; *cp && !any(*cp, "@:!."); cp++)
                ;
        if (*cp == '\0') {
                /* this is a local to local talk */
                his_name = argv[1];
                his_machine_name = my_machine_name;
        } else {
                if (*cp++ == '@') {
                        /* user@host */
                        his_name = argv[1];
                        his_machine_name = cp;
                } else {
                        /* host.user or host!user or host:user */
                        his_name = cp;
                        his_machine_name = argv[1];
                }
                *--cp = '\0';
        }
        if (argc > 2)
                his_tty = argv[2];      /* tty name is arg 2 */
        else
                his_tty = "";
        get_addrs(my_machine_name, his_machine_name);
        /*
         * Initialize the message template.
         */
        msg.vers = TALK_VERSION;
        msg.addr.sa_family = htons(AF_INET);
        msg.ctl_addr.sa_family = htons(AF_INET);
        msg.id_num = htonl(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';
}

static
any(c, cp)
        register char c, *cp;
{

        while (*cp)
                if (c == *cp++)
                        return (1);
        return (0);
}