/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 1997 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*LINTLIBRARY*/
/*
* chkinput()
*
* Routine to check to see if any input is waiting.
* It returns a 1 if there is input waiting, and a zero if
* no input is waiting.
*
* This function replaces system calls to ioctl() with the FIONREAD
* parameter. It enables curses to stop a screen refresh whenever
* a character is input.
* Standard BTL UNIX 4.0 or 5.0 does not handle FIONREAD.
* Changes have been made to 'wrefresh.c' to
* call this routine as "_inputpending = chkinput()".
* (delay.c and getch.c also use FIONREAD for nodelay, select and fast peek,
* but these routines have not been changed).
*
* Philip N. Crusius - July 20, 1983
* Modified to handle various systems March 9, 1984 by Mark Horton.
*/
#include <unistd.h>
#include <sys/types.h>
#include "curses_inc.h"
#ifdef FIONREAD
#define HAVE_CHK
int
_chkinput(void)
{
int i;
ioctl(SP->check_fd, FIONREAD, &i);
return (i > 0);
}
#endif /* FIONREAD */
#ifdef SELECT
#ifndef HAVE_CHK
#define HAVE_CHK
int
_chkinput(void)
{
int ifds, ofds, efds, n;
struct timeval tv;
ifds = 1 << SP->check_fd;
ofds = efds = 0;
tv.tv_sec = tv.t_usec = 0;
n = select(20, &ifds, &ofds, &efds, &tv);
return (n > 0);
}
#endif /* HAVE_CHK */
#endif /* SELECT */
#ifndef HAVE_CHK
#ifdef SYSV
int
_chkinput(void)
{
unsigned char c; /* character input */
/*
* Only check typeahead if the user is using our input
* routines. This is because the read below will put
* stuff into the inputQ that will never be read and the
* screen will never get updated from now on.
* This code should GO AWAY when a poll() or FIONREAD can
* be done on the file descriptor as then the check
* will be non-destructive.
*/
if (!cur_term->fl_typeahdok ||
(cur_term->_chars_on_queue == INP_QSIZE) ||
(cur_term->_check_fd < 0)) {
goto bad;
}
/* If input is waiting in curses queue, return (TRUE). */
if ((int)cur_term->_chars_on_queue > 0) {
#ifdef DEBUG
if (outf) {
(void) fprintf(outf, "Found a character on the input "
"queue\n");
_print_queue();
}
#endif /* DEBUG */
goto good;
}
if (read(cur_term->_check_fd, (char *)&c, 1) > 0) {
#ifdef DEBUG
if (outf) {
(void) fprintf(outf, "Reading ahead\n");
}
#endif /* DEBUG */
/*
* A character was waiting. Put it at the end
* of the curses queue and return 1 to show that
* input is waiting.
*/
#ifdef DEBUG
if (outf)
_print_queue();
#endif /* DEBUG */
cur_term->_input_queue[cur_term->_chars_on_queue++] = c;
good:
return (TRUE);
} else {
/* No input was waiting so return 0. */
#ifdef DEBUG
if (outf)
(void) fprintf(outf, "No input waiting\n");
#endif /* DEBUG */
bad:
return (FALSE);
}
}
#else /* SYSV */
int
_chkinput()
{
return (FALSE);
}
#endif /* SYSV */
#endif /* HAVE_CHK */
#ifdef DEBUG
void
_print_queue() /* FOR DEBUG ONLY */
{
int i, j = cur_term->_chars_on_queue;
chtype *inputQ = cur_term->_input_queue;
if (outf)
for (i = 0; i < j; i++)
(void) fprintf(outf, "inputQ[%d] = %c\n", i, inputQ[i]);
}
#endif /* DEBUG */