17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
57c478bd9Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
67c478bd9Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
77c478bd9Sstevel@tonic-gate  * with the License.
87c478bd9Sstevel@tonic-gate  *
97c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
107c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
117c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
127c478bd9Sstevel@tonic-gate  * and limitations under the License.
137c478bd9Sstevel@tonic-gate  *
147c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
157c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
167c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
177c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
187c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
197c478bd9Sstevel@tonic-gate  *
207c478bd9Sstevel@tonic-gate  * CDDL HEADER END
217c478bd9Sstevel@tonic-gate  */
227c478bd9Sstevel@tonic-gate /*
237c478bd9Sstevel@tonic-gate  * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
277c478bd9Sstevel@tonic-gate /*	Copyright (c) 1988 AT&T	*/
287c478bd9Sstevel@tonic-gate /*	  All Rights Reserved	*/
297c478bd9Sstevel@tonic-gate 
307c478bd9Sstevel@tonic-gate /*
317c478bd9Sstevel@tonic-gate  * University Copyright- Copyright (c) 1982, 1986, 1988
327c478bd9Sstevel@tonic-gate  * The Regents of the University of California
337c478bd9Sstevel@tonic-gate  * All Rights Reserved
347c478bd9Sstevel@tonic-gate  *
357c478bd9Sstevel@tonic-gate  * University Acknowledgment- Portions of this document are derived from
367c478bd9Sstevel@tonic-gate  * software developed by the University of California, Berkeley, and its
377c478bd9Sstevel@tonic-gate  * contributors.
387c478bd9Sstevel@tonic-gate  */
397c478bd9Sstevel@tonic-gate 
407c478bd9Sstevel@tonic-gate /*LINTLIBRARY*/
417c478bd9Sstevel@tonic-gate 
427c478bd9Sstevel@tonic-gate #include	<unistd.h>
437c478bd9Sstevel@tonic-gate #include	<sys/types.h>
447c478bd9Sstevel@tonic-gate #include	"curses_inc.h"
45*9c88ac3aSToomas Soome #ifdef SYSV
46*9c88ac3aSToomas Soome #include	<fcntl.h>
47*9c88ac3aSToomas Soome #endif /* SYSV */
487c478bd9Sstevel@tonic-gate 
497c478bd9Sstevel@tonic-gate /*
507c478bd9Sstevel@tonic-gate  * Set the file descriptor for typeahead checks to fd.  fd can be -1
517c478bd9Sstevel@tonic-gate  * to disable the checking.
527c478bd9Sstevel@tonic-gate  */
537c478bd9Sstevel@tonic-gate 
547c478bd9Sstevel@tonic-gate int
typeahead(int fd)557c478bd9Sstevel@tonic-gate typeahead(int fd)
567c478bd9Sstevel@tonic-gate {
577c478bd9Sstevel@tonic-gate #ifdef	SYSV
587c478bd9Sstevel@tonic-gate 	/*
597c478bd9Sstevel@tonic-gate 	 * Doing fcntls before and after each typeahead check
607c478bd9Sstevel@tonic-gate 	 * read is a serious problem on the 3b2. Profiling
617c478bd9Sstevel@tonic-gate 	 * results indicated that a simple program(edit.c from
627c478bd9Sstevel@tonic-gate 	 * "The New Curses and Terminfo Package") was spending
637c478bd9Sstevel@tonic-gate 	 * 9.2% of the time in fcntl().
647c478bd9Sstevel@tonic-gate 	 */
657c478bd9Sstevel@tonic-gate 
667c478bd9Sstevel@tonic-gate 	int	savefd = cur_term->_check_fd;
677c478bd9Sstevel@tonic-gate 
687c478bd9Sstevel@tonic-gate 	/* Close the previous duped file descriptor. */
697c478bd9Sstevel@tonic-gate 	if (savefd >= 0)
707c478bd9Sstevel@tonic-gate 		(void) close(savefd);
717c478bd9Sstevel@tonic-gate 
727c478bd9Sstevel@tonic-gate 	/*
737c478bd9Sstevel@tonic-gate 	 * Duplicate the file descriptor so we have one to play with.
747c478bd9Sstevel@tonic-gate 	 * We cannot use dup(2), unfortunately, so we do typeahead checking
757c478bd9Sstevel@tonic-gate 	 * on terminals only. Besides, if typeahead is done when input is
767c478bd9Sstevel@tonic-gate 	 * coming from a file, nothing would EVER get drawn on the screen!
777c478bd9Sstevel@tonic-gate 	 */
787c478bd9Sstevel@tonic-gate 
797c478bd9Sstevel@tonic-gate 	/* MODIFIED: DRS 3/26/89 */
807c478bd9Sstevel@tonic-gate 
817c478bd9Sstevel@tonic-gate 	/*
827c478bd9Sstevel@tonic-gate 	 * a couple of notes by DRS:  first, a new file descriptor is
837c478bd9Sstevel@tonic-gate 	 * required, since O_NDELAY must be set.  calling fcntl() or dup()
847c478bd9Sstevel@tonic-gate 	 * would provide a new file descriptor, but NOT a new file pointer
857c478bd9Sstevel@tonic-gate 	 * for the open file (by file pointer, i mean a unix kernal file
867c478bd9Sstevel@tonic-gate 	 * ptr).  if a new underlying unix file ptr. is not allocated,
877c478bd9Sstevel@tonic-gate 	 * setting O_NDELAY will cause all normal terminal i/o to return
887c478bd9Sstevel@tonic-gate 	 * prematurely without blocking.
897c478bd9Sstevel@tonic-gate 	 *
907c478bd9Sstevel@tonic-gate 	 * second, the call to ttyname is NOT necessary, /dev/tty can be
917c478bd9Sstevel@tonic-gate 	 * used instead.  calling ttyname is quite expensive -- especially
927c478bd9Sstevel@tonic-gate 	 * for large /dev directories.
937c478bd9Sstevel@tonic-gate 	 *
947c478bd9Sstevel@tonic-gate 	 * note also that the code for the '#else' clause will not work
957c478bd9Sstevel@tonic-gate 	 * since the new file descriptor MUST have O_NDELAY set for the
967c478bd9Sstevel@tonic-gate 	 * rest of libcurses code to function properly.
977c478bd9Sstevel@tonic-gate 	 *
987c478bd9Sstevel@tonic-gate 	 * 4/24/89:  modified to set the close on exec() flag of the newly
997c478bd9Sstevel@tonic-gate 	 * 		opened file descriptor
1007c478bd9Sstevel@tonic-gate 	 */
1017c478bd9Sstevel@tonic-gate 
1027c478bd9Sstevel@tonic-gate 	/*
1037c478bd9Sstevel@tonic-gate 	 *	cur_term->_check_fd = (tty = ttyname(fd)) ?
1047c478bd9Sstevel@tonic-gate 	 *	    open(tty, O_RDONLY | O_NDELAY) : -1;
1057c478bd9Sstevel@tonic-gate 	 */
1067c478bd9Sstevel@tonic-gate 	if (isatty(fd)) {
1077c478bd9Sstevel@tonic-gate 		if ((cur_term->_check_fd = open("/dev/tty", O_RDONLY |
1087c478bd9Sstevel@tonic-gate 		    O_NDELAY)) >= 0)
1097c478bd9Sstevel@tonic-gate 			(void) fcntl(cur_term->_check_fd, F_SETFD, 1);
1107c478bd9Sstevel@tonic-gate 	} else
1117c478bd9Sstevel@tonic-gate 		cur_term->_check_fd = -1;
1127c478bd9Sstevel@tonic-gate 
1137c478bd9Sstevel@tonic-gate #else	/* SYSV */
1147c478bd9Sstevel@tonic-gate 	int savefd = cur_term->_check_fd;
1157c478bd9Sstevel@tonic-gate 	/* Only do typeahead checking if the input is a tty. */
1167c478bd9Sstevel@tonic-gate 	if (isatty(fd))
1177c478bd9Sstevel@tonic-gate 		cur_term->_check_fd = fd;
1187c478bd9Sstevel@tonic-gate 	else
1197c478bd9Sstevel@tonic-gate 		cur_term->_check_fd = -1;
1207c478bd9Sstevel@tonic-gate #endif	/* SYSV */
1217c478bd9Sstevel@tonic-gate 	return (savefd);
1227c478bd9Sstevel@tonic-gate }
123