1 /**************************************************************************** 2 * Copyright 2020 Thomas E. Dickey * 3 * Copyright 1998-2011,2012 Free Software Foundation, Inc. * 4 * * 5 * Permission is hereby granted, free of charge, to any person obtaining a * 6 * copy of this software and associated documentation files (the * 7 * "Software"), to deal in the Software without restriction, including * 8 * without limitation the rights to use, copy, modify, merge, publish, * 9 * distribute, distribute with modifications, sublicense, and/or sell * 10 * copies of the Software, and to permit persons to whom the Software is * 11 * furnished to do so, subject to the following conditions: * 12 * * 13 * The above copyright notice and this permission notice shall be included * 14 * in all copies or substantial portions of the Software. * 15 * * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * 19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * 20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * 21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * 22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * 23 * * 24 * Except as contained in this notice, the name(s) of the above copyright * 25 * holders shall not be used in advertising or otherwise to promote the * 26 * sale, use or other dealings in this Software without prior written * 27 * authorization. * 28 ****************************************************************************/ 29 30 /**************************************************************************** 31 * Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 * 32 * and: Eric S. Raymond <esr@snark.thyrsus.com> * 33 * and: Thomas E. Dickey 1996-on * 34 * and: Juergen Pfeifer 2009 * 35 ****************************************************************************/ 36 37 /* 38 ** lib_ungetch.c 39 ** 40 ** The routine ungetch(). 41 ** 42 */ 43 44 #include <curses.priv.h> 45 46 MODULE_ID("$Id: lib_ungetch.c,v 1.17 2020/02/02 23:34:34 tom Exp $") 47 48 #include <fifo_defs.h> 49 50 #ifdef TRACE 51 NCURSES_EXPORT(void) 52 _nc_fifo_dump(SCREEN *sp) 53 { 54 int i; 55 T(("head = %d, tail = %d, peek = %d", head, tail, peek)); 56 for (i = 0; i < 10; i++) 57 T(("char %d = %s", i, _nc_tracechar(sp, sp->_fifo[i]))); 58 } 59 #endif /* TRACE */ 60 61 NCURSES_EXPORT(int) 62 safe_ungetch(SCREEN *sp, int ch) 63 { 64 int rc = ERR; 65 66 T((T_CALLED("ungetch(%p,%s)"), (void *) sp, _nc_tracechar(sp, ch))); 67 68 if (sp != 0 && tail >= 0) { 69 if (head < 0) { 70 head = 0; 71 t_inc(); 72 peek = tail; /* no raw keys */ 73 } else { 74 h_dec(); 75 } 76 77 sp->_fifo[head] = ch; 78 T(("ungetch %s ok", _nc_tracechar(sp, ch))); 79 #ifdef TRACE 80 if (USE_TRACEF(TRACE_IEVENT)) { 81 _nc_fifo_dump(sp); 82 _nc_unlock_global(tracef); 83 } 84 #endif 85 rc = OK; 86 } 87 returnCode(rc); 88 } 89 90 NCURSES_EXPORT(int) 91 ungetch(int ch) 92 { 93 return safe_ungetch(CURRENT_SCREEN, ch); 94 } 95