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-rw-r--r--utf8.c326
1 files changed, 326 insertions, 0 deletions
diff --git a/utf8.c b/utf8.c
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+++ b/utf8.c
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+#ifdef TLF_FONTS
+/*
+ * Copyright (c) 2007 Alexey Vatchenko <av@bsdua.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include <sys/types.h>
+
+#include <wchar.h>
+#include <arpa/inet.h> /* for htonl() */
+
+#include "utf8.h"
+
+#define _NXT 0x80
+#define _SEQ2 0xc0
+#define _SEQ3 0xe0
+#define _SEQ4 0xf0
+#define _SEQ5 0xf8
+#define _SEQ6 0xfc
+
+#define _BOM 0xfeff
+
+static int __wchar_forbitten(wchar_t sym);
+static int __utf8_forbitten(u_char octet);
+
+static int
+__wchar_forbitten(wchar_t sym)
+{
+
+ /* Surrogate pairs */
+ if (sym >= 0xd800 && sym <= 0xdfff)
+ return (-1);
+
+ return (0);
+}
+
+static int
+__utf8_forbitten(u_char octet)
+{
+
+ switch (octet) {
+ case 0xc0:
+ case 0xc1:
+ case 0xf5:
+ case 0xff:
+ return (-1);
+ }
+
+ return (0);
+}
+
+/*
+ * DESCRIPTION
+ * This function translates UTF-8 string into UCS-4 string (all symbols
+ * will be in local machine byte order).
+ *
+ * It takes the following arguments:
+ * in - input UTF-8 string. It can be null-terminated.
+ * insize - size of input string in bytes.
+ * out - result buffer for UCS-4 string. If out is NULL,
+ * function returns size of result buffer.
+ * outsize - size of out buffer in wide characters.
+ *
+ * RETURN VALUES
+ * The function returns size of result buffer (in wide characters).
+ * Zero is returned in case of error.
+ *
+ * CAVEATS
+ * 1. If UTF-8 string contains zero symbols, they will be translated
+ * as regular symbols.
+ * 2. If UTF8_IGNORE_ERROR or UTF8_SKIP_BOM flag is set, sizes may vary
+ * when `out' is NULL and not NULL. It's because of special UTF-8
+ * sequences which may result in forbitten (by RFC3629) UNICODE
+ * characters. So, the caller must check return value every time and
+ * not prepare buffer in advance (\0 terminate) but after calling this
+ * function.
+ */
+size_t
+utf8_to_wchar(const char *in, size_t insize, wchar_t *out, size_t outsize,
+ int flags)
+{
+ u_char *p, *lim;
+ wchar_t *wlim, high;
+ size_t n, total, i, n_bits;
+
+ if (in == NULL || insize == 0 || (outsize == 0 && out != NULL))
+ return (0);
+
+ total = 0;
+ p = (u_char *)in;
+ lim = p + insize;
+ wlim = out + outsize;
+
+ for (; p < lim; p += n) {
+ if (__utf8_forbitten(*p) != 0 &&
+ (flags & UTF8_IGNORE_ERROR) == 0)
+ return (0);
+
+ /*
+ * Get number of bytes for one wide character.
+ */
+ n = 1; /* default: 1 byte. Used when skipping bytes. */
+ if ((*p & 0x80) == 0)
+ high = (wchar_t)*p;
+ else if ((*p & 0xe0) == _SEQ2) {
+ n = 2;
+ high = (wchar_t)(*p & 0x1f);
+ } else if ((*p & 0xf0) == _SEQ3) {
+ n = 3;
+ high = (wchar_t)(*p & 0x0f);
+ } else if ((*p & 0xf8) == _SEQ4) {
+ n = 4;
+ high = (wchar_t)(*p & 0x07);
+ } else if ((*p & 0xfc) == _SEQ5) {
+ n = 5;
+ high = (wchar_t)(*p & 0x03);
+ } else if ((*p & 0xfe) == _SEQ6) {
+ n = 6;
+ high = (wchar_t)(*p & 0x01);
+ } else {
+ if ((flags & UTF8_IGNORE_ERROR) == 0)
+ return (0);
+ continue;
+ }
+
+ /* does the sequence header tell us truth about length? */
+ if (lim - p <= n - 1) {
+ if ((flags & UTF8_IGNORE_ERROR) == 0)
+ return (0);
+ n = 1;
+ continue; /* skip */
+ }
+
+ /*
+ * Validate sequence.
+ * All symbols must have higher bits set to 10xxxxxx
+ */
+ if (n > 1) {
+ for (i = 1; i < n; i++) {
+ if ((p[i] & 0xc0) != _NXT)
+ break;
+ }
+ if (i != n) {
+ if ((flags & UTF8_IGNORE_ERROR) == 0)
+ return (0);
+ n = 1;
+ continue; /* skip */
+ }
+ }
+
+ total++;
+
+ if (out == NULL)
+ continue;
+
+ if (out >= wlim)
+ return (0); /* no space left */
+
+ *out = 0;
+ n_bits = 0;
+ for (i = 1; i < n; i++) {
+ *out |= (wchar_t)(p[n - i] & 0x3f) << n_bits;
+ n_bits += 6; /* 6 low bits in every byte */
+ }
+ *out |= high << n_bits;
+
+ if (*out == 0) /* return at end of string */
+ break;
+
+ if (__wchar_forbitten(*out) != 0) {
+ if ((flags & UTF8_IGNORE_ERROR) == 0)
+ return (0); /* forbitten character */
+ else {
+ total--;
+ out--;
+ }
+ } else if (*out == _BOM && (flags & UTF8_SKIP_BOM) != 0) {
+ total--;
+ out--;
+ }
+
+ out++;
+ }
+
+ return (total);
+}
+
+/*
+ * DESCRIPTION
+ * This function translates UCS-4 symbols (given in local machine
+ * byte order) into UTF-8 string.
+ *
+ * It takes the following arguments:
+ * in - input unicode string. It can be null-terminated.
+ * insize - size of input string in wide characters.
+ * out - result buffer for utf8 string. If out is NULL,
+ * function returns size of result buffer.
+ * outsize - size of result buffer.
+ *
+ * RETURN VALUES
+ * The function returns size of result buffer (in bytes). Zero is returned
+ * in case of error.
+ *
+ * CAVEATS
+ * If UCS-4 string contains zero symbols, they will be translated
+ * as regular symbols.
+ */
+size_t
+wchar_to_utf8(const wchar_t *in, size_t insize, char *out, size_t outsize,
+ int flags)
+{
+ wchar_t *w, *wlim, ch;
+ u_char *p, *lim, *oc;
+ size_t total, n;
+
+ if (in == NULL || insize == 0 || (outsize == 0 && out != NULL))
+ return (0);
+
+ w = (wchar_t *)in;
+ wlim = w + insize;
+ p = (u_char *)out;
+ lim = p + outsize;
+ total = 0;
+ for (; w < wlim; w++) {
+ if (__wchar_forbitten(*w) != 0) {
+ if ((flags & UTF8_IGNORE_ERROR) == 0)
+ return (0);
+ else
+ continue;
+ }
+
+ if (*w == _BOM && (flags & UTF8_SKIP_BOM) != 0)
+ continue;
+
+ if (*w < 0) {
+ if ((flags & UTF8_IGNORE_ERROR) == 0)
+ return (0);
+ continue;
+ } else if (*w <= 0x0000007f)
+ n = 1;
+ else if (*w <= 0x000007ff)
+ n = 2;
+ else if (*w <= 0x0000ffff)
+ n = 3;
+ else if (*w <= 0x001fffff)
+ n = 4;
+ else if (*w <= 0x03ffffff)
+ n = 5;
+ else /* if (*w <= 0x7fffffff) */
+ n = 6;
+
+ total += n;
+
+ if (out == NULL)
+ continue;
+
+ if (lim - p <= n - 1)
+ return (0); /* no space left */
+
+ /* make it work under different endians */
+ ch = htonl(*w);
+ oc = (u_char *)&ch;
+ switch (n) {
+ case 1:
+ *p = oc[3];
+ break;
+
+ case 2:
+ p[1] = _NXT | (oc[3] & 0x3f);
+ p[0] = _SEQ2 | (oc[3] >> 6) | ((oc[2] & 0x07) << 2);
+ break;
+
+ case 3:
+ p[2] = _NXT | (oc[3] & 0x3f);
+ p[1] = _NXT | (oc[3] >> 6) | ((oc[2] & 0x0f) << 2);
+ p[0] = _SEQ3 | ((oc[2] & 0xf0) >> 4);
+ break;
+
+ case 4:
+ p[3] = _NXT | (oc[3] & 0x3f);
+ p[2] = _NXT | (oc[3] >> 6) | ((oc[2] & 0x0f) << 2);
+ p[1] = _NXT | ((oc[2] & 0xf0) >> 4) |
+ ((oc[1] & 0x03) << 4);
+ p[0] = _SEQ4 | ((oc[1] & 0x1f) >> 2);
+ break;
+
+ case 5:
+ p[4] = _NXT | (oc[3] & 0x3f);
+ p[3] = _NXT | (oc[3] >> 6) | ((oc[2] & 0x0f) << 2);
+ p[2] = _NXT | ((oc[2] & 0xf0) >> 4) |
+ ((oc[1] & 0x03) << 4);
+ p[1] = _NXT | (oc[1] >> 2);
+ p[0] = _SEQ5 | (oc[0] & 0x03);
+ break;
+
+ case 6:
+ p[5] = _NXT | (oc[3] & 0x3f);
+ p[4] = _NXT | (oc[3] >> 6) | ((oc[2] & 0x0f) << 2);
+ p[3] = _NXT | (oc[2] >> 4) | ((oc[1] & 0x03) << 4);
+ p[2] = _NXT | (oc[1] >> 2);
+ p[1] = _NXT | (oc[0] & 0x3f);
+ p[0] = _SEQ6 | ((oc[0] & 0x40) >> 6);
+ break;
+ }
+
+ /*
+ * NOTE: do not check here for forbitten UTF-8 characters.
+ * They cannot appear here because we do proper convertion.
+ */
+
+ p += n;
+ }
+
+ return (total);
+}
+#endif /* TLF_FONTS */
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