summary refs log tree commit diff
path: root/pls.c
blob: 08309f86bfcd14383734baae99cf9adca0c82b32 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
/* Copyright (C) 2018  Curtis McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <wchar.h>

#include "chat.h"

wchar_t *wcsnchr(const wchar_t *wcs, size_t len, wchar_t chr) {
	len = wcsnlen(wcs, len);
	for (size_t i = 0; i < len; ++i) {
		if (wcs[i] == chr) return (wchar_t *)&wcs[i];
	}
	return NULL;
}

wchar_t *wcsnrchr(const wchar_t *wcs, size_t len, wchar_t chr) {
	len = wcsnlen(wcs, len);
	for (size_t i = len - 1; i < len; --i) {
		if (wcs[i] == chr) return (wchar_t *)&wcs[i];
	}
	return NULL;
}

wchar_t *ambstowcs(const char *src) {
	size_t len = mbsrtowcs(NULL, &src, 0, NULL);
	if (len == (size_t)-1) return NULL;

	wchar_t *dst = malloc(sizeof(*dst) * (1 + len));
	if (!dst) return NULL;

	len = mbsrtowcs(dst, &src, 1 + len, NULL);
	if (len == (size_t)-1) {
		free(dst);
		return NULL;
	}

	return dst;
}

char *awcstombs(const wchar_t *src) {
	size_t len = wcsrtombs(NULL, &src, 0, NULL);
	if (len == (size_t)-1) return NULL;

	char *dst = malloc(sizeof(*dst) * (1 + len));
	if (!dst) return NULL;

	len = wcsrtombs(dst, &src, 1 + len, NULL);
	if (len == (size_t)-1) {
		free(dst);
		return NULL;
	}

	return dst;
}

char *awcsntombs(const wchar_t *src, size_t nwc) {
	size_t len = wcsnrtombs(NULL, &src, nwc, 0, NULL);
	if (len == (size_t)-1) return NULL;

	char *dst = malloc(sizeof(*dst) * (1 + len));
	if (!dst) return NULL;

	len = wcsnrtombs(dst, &src, nwc, 1 + len, NULL);
	if (len == (size_t)-1) {
		free(dst);
		return NULL;
	}

	return dst;
}

// From <https://en.cppreference.com/w/c/io/fwprintf#Notes>:
//
// While narrow strings provide snprintf, which makes it possible to determine
// the required output buffer size, there is no equivalent for wide strings
// (until C11's snwprintf_s), and in order to determine the buffer size, the
// program may need to call swprintf, check the result value, and reallocate a
// larger buffer, trying again until successful.
//
// snwprintf_s, unlike swprintf_s, will truncate the result to fit within the
// array pointed to by buffer, even though truncation is treated as an error by
// most bounds-checked functions.
int vaswprintf(wchar_t **ret, const wchar_t *format, va_list ap) {
	*ret = NULL;

	for (size_t cap = 2 * wcslen(format);; cap *= 2) {
		wchar_t *buf = realloc(*ret, sizeof(*buf) * (1 + cap));
		if (!buf) goto fail;
		*ret = buf;

		va_list _ap;
		va_copy(_ap, ap);
		errno = EOVERFLOW; // vswprintf may not set errno.
		int len = vswprintf(*ret, 1 + cap, format, _ap);
		va_end(_ap);

		if (len >= 0) return len;
		if (errno != EOVERFLOW) goto fail;
	}

fail:
	free(*ret);
	*ret = NULL;
	return -1;
}