1 /* $OpenBSD: lib_unget_wch.c,v 1.2 2023/10/17 09:52:09 nicm Exp $ */
2 
3 /****************************************************************************
4  * Copyright 2020,2023 Thomas E. Dickey                                     *
5  * Copyright 2002-2011,2016 Free Software Foundation, Inc.                  *
6  *                                                                          *
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12  * copies of the Software, and to permit persons to whom the Software is    *
13  * furnished to do so, subject to the following conditions:                 *
14  *                                                                          *
15  * The above copyright notice and this permission notice shall be included  *
16  * in all copies or substantial portions of the Software.                   *
17  *                                                                          *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
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31 
32 /****************************************************************************
33  *  Author: Thomas E. Dickey 2002                                           *
34  ****************************************************************************/
35 
36 /*
37 **	lib_unget_wch.c
38 **
39 **	The routine unget_wch().
40 **
41 */
42 
43 #include <curses.priv.h>
44 
45 MODULE_ID("$Id: lib_unget_wch.c,v 1.2 2023/10/17 09:52:09 nicm Exp $")
46 
47 /*
48  * Wrapper for wcrtomb() which obtains the length needed for the given
49  * wide-character 'source'.
50  */
51 NCURSES_EXPORT(size_t)
52 _nc_wcrtomb(char *target, wchar_t source, mbstate_t * state)
53 {
54     int result;
55 
56     if (target == 0) {
57 	wchar_t temp[2];
58 	const wchar_t *tempp = temp;
59 	temp[0] = source;
60 	temp[1] = 0;
61 	result = (int) wcsrtombs(NULL, &tempp, (size_t) 0, state);
62     } else {
63 	result = (int) wcrtomb(target, source, state);
64     }
65     if (!isEILSEQ(result) && ((result == 0) || (result > MB_LEN_MAX)))
66 	result = 1;
67     return (size_t) result;
68 }
69 
70 NCURSES_EXPORT(int)
71 NCURSES_SP_NAME(unget_wch) (NCURSES_SP_DCLx const wchar_t wch)
72 {
73     int result = OK;
74     mbstate_t state;
75     size_t length;
76 
77     T((T_CALLED("unget_wch(%p, %#lx)"), (void *) SP_PARM, (unsigned long) wch));
78 
79     init_mb(state);
80     length = _nc_wcrtomb(0, wch, &state);
81 
82     if (length != (size_t) (-1)
83 	&& length != 0) {
84 	char *string;
85 
86 	if ((string = (char *) malloc(length)) != 0) {
87 	    int n;
88 
89 	    init_mb(state);
90 	    /* ignore the result, since we already validated the character */
91 	    IGNORE_RC((int) wcrtomb(string, wch, &state));
92 
93 	    for (n = (int) (length - 1); n >= 0; --n) {
94 		if (NCURSES_SP_NAME(ungetch) (NCURSES_SP_ARGx
95 					      UChar(string[n])) !=OK) {
96 		    result = ERR;
97 		    break;
98 		}
99 	    }
100 	    free(string);
101 	} else {
102 	    result = ERR;
103 	}
104     } else {
105 	result = ERR;
106     }
107 
108     returnCode(result);
109 }
110 
111 #if NCURSES_SP_FUNCS
112 NCURSES_EXPORT(int)
113 unget_wch(const wchar_t wch)
114 {
115     return NCURSES_SP_NAME(unget_wch) (CURRENT_SCREEN, wch);
116 }
117 #endif
118