xref: /freebsd/contrib/ncurses/ncurses/widechar/lib_unget_wch.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /****************************************************************************
2  * Copyright 2020 Thomas E. Dickey                                          *
3  * Copyright 2002-2011,2016 Free Software Foundation, Inc.                  *
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29 
30 /****************************************************************************
31  *  Author: Thomas E. Dickey 2002                                           *
32  ****************************************************************************/
33 
34 /*
35 **	lib_unget_wch.c
36 **
37 **	The routine unget_wch().
38 **
39 */
40 
41 #include <curses.priv.h>
42 
43 MODULE_ID("$Id: lib_unget_wch.c,v 1.17 2020/02/02 23:34:34 tom Exp $")
44 
45 /*
46  * Wrapper for wcrtomb() which obtains the length needed for the given
47  * wide-character 'source'.
48  */
49 NCURSES_EXPORT(size_t)
50 _nc_wcrtomb(char *target, wchar_t source, mbstate_t * state)
51 {
52     int result;
53 
54     if (target == 0) {
55 	wchar_t temp[2];
56 	const wchar_t *tempp = temp;
57 	temp[0] = source;
58 	temp[1] = 0;
59 	result = (int) wcsrtombs(NULL, &tempp, (size_t) 0, state);
60     } else {
61 	result = (int) wcrtomb(target, source, state);
62     }
63     if (!isEILSEQ(result) && (result == 0))
64 	result = 1;
65     return (size_t) result;
66 }
67 
68 NCURSES_EXPORT(int)
69 NCURSES_SP_NAME(unget_wch) (NCURSES_SP_DCLx const wchar_t wch)
70 {
71     int result = OK;
72     mbstate_t state;
73     size_t length;
74 
75     T((T_CALLED("unget_wch(%p, %#lx)"), (void *) SP_PARM, (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 	    int n;
86 
87 	    init_mb(state);
88 	    /* ignore the result, since we already validated the character */
89 	    IGNORE_RC((int) wcrtomb(string, wch, &state));
90 
91 	    for (n = (int) (length - 1); n >= 0; --n) {
92 		if (NCURSES_SP_NAME(ungetch) (NCURSES_SP_ARGx
93 					      UChar(string[n])) !=OK) {
94 		    result = ERR;
95 		    break;
96 		}
97 	    }
98 	    free(string);
99 	} else {
100 	    result = ERR;
101 	}
102     } else {
103 	result = ERR;
104     }
105 
106     returnCode(result);
107 }
108 
109 #if NCURSES_SP_FUNCS
110 NCURSES_EXPORT(int)
111 unget_wch(const wchar_t wch)
112 {
113     return NCURSES_SP_NAME(unget_wch) (CURRENT_SCREEN, wch);
114 }
115 #endif
116