4.3BSD-Reno/src/usr.bin/tip/hunt.c

/*
 * Copyright (c) 1983 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that: (1) source distributions retain this entire copyright
 * notice and comment, and (2) distributions including binaries display
 * the following acknowledgement:  ``This product includes software
 * developed by the University of California, Berkeley and its contributors''
 * in the documentation or other materials provided with the distribution
 * and in all advertising materials mentioning features or use of this
 * software. Neither the name of the University nor the names of its
 * contributors may 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 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char sccsid[] = "@(#)hunt.c	5.6 (Berkeley) 6/1/90";
#endif /* not lint */

#include "tip.h"

extern char *getremote();
extern char *rindex();

static	jmp_buf deadline;
static	int deadfl;

void
dead()
{
	deadfl = 1;
	longjmp(deadline, 1);
}

hunt(name)
	char *name;
{
	register char *cp;
	sig_t f;

	f = signal(SIGALRM, dead);
	while (cp = getremote(name)) {
		deadfl = 0;
		uucplock = rindex(cp, '/')+1;
		if (uu_lock(uucplock) < 0)
			continue;
		/*
		 * Straight through call units, such as the BIZCOMP,
		 * VADIC and the DF, must indicate they're hardwired in
		 *  order to get an open file descriptor placed in FD.
		 * Otherwise, as for a DN-11, the open will have to
		 *  be done in the "open" routine.
		 */
		if (!HW)
			break;
		if (setjmp(deadline) == 0) {
			alarm(10);
			FD = open(cp, O_RDWR);
		}
		alarm(0);
		if (FD < 0) {
			perror(cp);
			deadfl = 1;
		}
		if (!deadfl) {
			ioctl(FD, TIOCEXCL, 0);
			ioctl(FD, TIOCHPCL, 0);
			signal(SIGALRM, SIG_DFL);
			return ((int)cp);
		}
		(void)uu_unlock(uucplock);
	}
	signal(SIGALRM, f);
	return (deadfl ? -1 : (int)cp);
}