1 /****************************************************************************
2 * Copyright (c) 1998-2001,2002 Free Software Foundation, Inc. *
3 * *
4 * Permission is hereby granted, free of charge, to any person obtaining a *
5 * copy of this software and associated documentation files (the *
6 * "Software"), to deal in the Software without restriction, including *
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8 * distribute, distribute with modifications, sublicense, and/or sell *
9 * copies of the Software, and to permit persons to whom the Software is *
10 * furnished to do so, subject to the following conditions: *
11 * *
12 * The above copyright notice and this permission notice shall be included *
13 * in all copies or substantial portions of the Software. *
14 * *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
16 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
18 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
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21 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
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23 * Except as contained in this notice, the name(s) of the above copyright *
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27 ****************************************************************************/
28
29 /****************************************************************************
30 * Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 *
31 * and: Eric S. Raymond <esr@snark.thyrsus.com> *
32 ****************************************************************************/
33
34 /*
35 ** lib_ungetch.c
36 **
37 ** The routine ungetch().
38 **
39 */
40
41 #include <curses.priv.h>
42
43 MODULE_ID("$Id: lib_ungetch.c,v 1.8 2002/08/24 22:08:48 tom Exp $")
44
45 #include <fifo_defs.h>
46
47 #ifdef TRACE
NCURSES_EXPORT(void)48 NCURSES_EXPORT(void)
49 _nc_fifo_dump(void)
50 {
51 int i;
52 T(("head = %d, tail = %d, peek = %d", head, tail, peek));
53 for (i = 0; i < 10; i++)
54 T(("char %d = %s", i, _tracechar(SP->_fifo[i])));
55 }
56 #endif /* TRACE */
57
58 NCURSES_EXPORT(int)
ungetch(int ch)59 ungetch(int ch)
60 {
61 T((T_CALLED("ungetch(%s)"), _tracechar(ch)));
62
63 if (tail == -1)
64 returnCode(ERR);
65 if (head == -1) {
66 head = 0;
67 t_inc()
68 peek = tail; /* no raw keys */
69 } else
70 h_dec();
71
72 SP->_fifo[head] = ch;
73 T(("ungetch %s ok", _tracechar(ch)));
74 #ifdef TRACE
75 if (_nc_tracing & TRACE_IEVENT)
76 _nc_fifo_dump();
77 #endif
78 returnCode(OK);
79 }
80