xref: /freebsd/contrib/ncurses/ncurses/widechar/lib_unget_wch.c (revision 9336e0699bda8a301cd2bfa37106b6ec5e32012e)
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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 1.7 2004/12/05 01:21:31 tom Exp $")
43 
44 #ifdef linux
45 /*
46  * glibc's wcrtomb() function is broken - does not return the proper value
47  * when target is null (noted for glibc 2.3.2).  This is a workaround.
48  */
49 NCURSES_EXPORT(size_t)
50 _nc_wcrtomb(char *target, wchar_t source, mbstate_t * state)
51 {
52     if (target == 0) {
53 	wchar_t temp[2];
54 	const wchar_t *tempp = temp;
55 	temp[0] = source;
56 	temp[1] = 0;
57 	return wcsrtombs(NULL, &tempp, 0, state);
58     }
59     return wcrtomb(target, source, state);
60 }
61 #endif
62 
63 NCURSES_EXPORT(int)
64 unget_wch(const wchar_t wch)
65 {
66     int result = OK;
67     mbstate_t state;
68     size_t length;
69     int n;
70 
71     T((T_CALLED("unget_wch(%#lx)"), (unsigned long) wch));
72 
73     init_mb(state);
74     length = _nc_wcrtomb(0, wch, &state);
75 
76     if (length != (size_t) (-1)
77 	&& length != 0) {
78 	char *string;
79 
80 	if ((string = (char *) malloc(length)) != 0) {
81 	    init_mb(state);
82 	    wcrtomb(string, wch, &state);
83 
84 	    for (n = (int) (length - 1); n >= 0; --n) {
85 		if (ungetch(string[n]) != OK) {
86 		    result = ERR;
87 		    break;
88 		}
89 	    }
90 	    free(string);
91 	} else {
92 	    result = ERR;
93 	}
94     } else {
95 	result = ERR;
96     }
97 
98     returnCode(result);
99 }
100