lib_unget_wch.c revision 174994 
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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
42MODULE_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 */
48NCURSES_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
67NCURSES_EXPORT(int)
68unget_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