catboy/pls.c

187 lines
4.7 KiB
C

/* Copyright (C) 2018 C. 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, len, NULL);
if (len == (size_t)-1) {
free(dst);
return NULL;
}
dst[len] = L'\0';
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, len, NULL);
if (len == (size_t)-1) {
free(dst);
return NULL;
}
dst[len] = '\0';
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, len, NULL);
if (len == (size_t)-1) {
free(dst);
return NULL;
}
dst[len] = '\0';
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;
}
int aswprintf(wchar_t **ret, const wchar_t *format, ...) {
va_list ap;
va_start(ap, format);
int n = vaswprintf(ret, format, ap);
va_end(ap);
return n;
}
static const char Base64[64] = {
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
};
size_t base64Size(size_t len) {
return 1 + (len + 2) / 3 * 4;
}
void base64(char *dst, const byte *src, size_t len) {
size_t i = 0;
while (len > 2) {
dst[i++] = Base64[0x3F & (src[0] >> 2)];
dst[i++] = Base64[0x3F & (src[0] << 4 | src[1] >> 4)];
dst[i++] = Base64[0x3F & (src[1] << 2 | src[2] >> 6)];
dst[i++] = Base64[0x3F & src[2]];
src += 3;
len -= 3;
}
if (len) {
dst[i++] = Base64[0x3F & (src[0] >> 2)];
if (len > 1) {
dst[i++] = Base64[0x3F & (src[0] << 4 | src[1] >> 4)];
dst[i++] = Base64[0x3F & (src[1] << 2)];
} else {
dst[i++] = Base64[0x3F & (src[0] << 4)];
dst[i++] = '=';
}
dst[i++] = '=';
}
dst[i] = '\0';
}
#ifdef TEST
#include <assert.h>
#include <string.h>
int main() {
assert(5 == base64Size(1));
assert(5 == base64Size(2));
assert(5 == base64Size(3));
assert(9 == base64Size(4));
char b64[base64Size(3)];
assert((base64(b64, (byte *)"cat", 3), !strcmp("Y2F0", b64)));
assert((base64(b64, (byte *)"ca", 2), !strcmp("Y2E=", b64)));
assert((base64(b64, (byte *)"c", 1), !strcmp("Yw==", b64)));
assert((base64(b64, (byte *)"\xFF\x00\xFF", 3), !strcmp("/wD/", b64)));
assert((base64(b64, (byte *)"\x00\xFF\x00", 3), !strcmp("AP8A", b64)));
}
#endif