xref: /freebsd/contrib/ncurses/ncurses/widechar/lib_unget_wch.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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28 
29 /****************************************************************************
30  *  Author: Thomas E. Dickey 2002                                           *
31  ****************************************************************************/
32 
33 /*
34 **	lib_unget_wch.c
35 **
36 **	The routine unget_wch().
37 **
38 */
39 
40 #include <curses.priv.h>
41 
42 MODULE_ID("$Id: lib_unget_wch.c,v 1.9 2007/11/25 00:57:00 tom Exp $")
43 
44 /*
45  * Wrapper for wcrtomb() which obtains the length needed for the given
46  * wide-character 'source'.
47  */
48 NCURSES_EXPORT(size_t)
49 _nc_wcrtomb(char *target, wchar_t source, mbstate_t * state)
50 {
51     int result;
52 
53     if (target == 0) {
54 	wchar_t temp[2];
55 	const wchar_t *tempp = temp;
56 	temp[0] = source;
57 	temp[1] = 0;
58 	result = wcsrtombs(NULL, &tempp, 0, state);
59     } else {
60 	result = wcrtomb(target, source, state);
61     }
62     if (!isEILSEQ(result) && (result == 0))
63 	result = 1;
64     return result;
65 }
66 
67 NCURSES_EXPORT(int)
68 unget_wch(const wchar_t wch)
69 {
70     int result = OK;
71     mbstate_t state;
72     size_t length;
73     int n;
74 
75     T((T_CALLED("unget_wch(%#lx)"), (unsigned long) wch));
76 
77     init_mb(state);
78     length = _nc_wcrtomb(0, wch, &state);
79 
80     if (length != (size_t) (-1)
81 	&& length != 0) {
82 	char *string;
83 
84 	if ((string = (char *) malloc(length)) != 0) {
85 	    init_mb(state);
86 	    wcrtomb(string, wch, &state);
87 
88 	    for (n = (int) (length - 1); n >= 0; --n) {
89 		if (ungetch(string[n]) != OK) {
90 		    result = ERR;
91 		    break;
92 		}
93 	    }
94 	    free(string);
95 	} else {
96 	    result = ERR;
97 	}
98     } else {
99 	result = ERR;
100     }
101 
102     returnCode(result);
103 }
104