#define _GP_UNICODE_C_ /* gutf8.c - Operations on UTF-8 strings. * * Copyright (C) 1999 Tom Tromey * Copyright (C) 2000 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include #include "gp-unicode.h" #include "string.h" #define UTF8_COMPUTE(Char, Mask, Len) \ if (Char < 128) \ { \ Len = 1; \ Mask = 0x7f; \ } \ else if ((Char & 0xe0) == 0xc0) \ { \ Len = 2; \ Mask = 0x1f; \ } \ else if ((Char & 0xf0) == 0xe0) \ { \ Len = 3; \ Mask = 0x0f; \ } \ else if ((Char & 0xf8) == 0xf0) \ { \ Len = 4; \ Mask = 0x07; \ } \ else if ((Char & 0xfc) == 0xf8) \ { \ Len = 5; \ Mask = 0x03; \ } \ else if ((Char & 0xfe) == 0xfc) \ { \ Len = 6; \ Mask = 0x01; \ } \ else \ Len = -1; #define UTF8_GET(Result, Chars, Count, Mask, Len) \ (Result) = (Chars)[0] & (Mask); \ for ((Count) = 1; (Count) < (Len); ++(Count)) \ { \ if (((Chars)[(Count)] & 0xc0) != 0x80) \ { \ (Result) = -1; \ break; \ } \ (Result) <<= 6; \ (Result) |= ((Chars)[(Count)] & 0x3f); \ } gchar g_utf8_skip[256] = { 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,0,0 }; /** * g_utf8_find_prev_char: * @str: pointer to the beginning of a UTF-8 string * @p: pointer to some position within @str * * Given a position @p with a UTF-8 encoded string @str, find the start * of the previous UTF-8 character starting before @p. Returns %NULL if no * UTF-8 characters are present in @p before @str. * * @p does not have to be at the beginning of a UTF-8 chracter. No check * is made to see if the character found is actually valid other than * it starts with an appropriate byte. * * Return value: a pointer to the found character or %NULL. **/ gchar * g_utf8_find_prev_char (const char *str, const char *p) { for (--p; p > str; --p) { if ((*p & 0xc0) != 0x80) return (gchar *)p; } return NULL; } /** * g_utf8_find_next_char: * @p: a pointer to a position within a UTF-8 encoded string * @end: a pointer to the end of the string, or %NULL to indicate * that the string is NULL terminated, in which case * the returned value will be * * Find the start of the next utf-8 character in the string after @p * * @p does not have to be at the beginning of a UTF-8 chracter. No check * is made to see if the character found is actually valid other than * it starts with an appropriate byte. * * Return value: a pointer to the found character or %NULL **/ gchar * g_utf8_find_next_char (const gchar *p, const gchar *end) { if (*p) { if (end) for (++p; p < end && (*p & 0xc0) == 0x80; ++p) ; else for (++p; (*p & 0xc0) == 0x80; ++p) ; } return (p == end) ? NULL : (gchar *)p; } /** * g_utf8_prev_char: * @p: a pointer to a position within a UTF-8 encoded string * * Find the previous UTF-8 character in the string before @p * * @p does not have to be at the beginning of a UTF-8 character. No check * is made to see if the character found is actually valid other than * it starts with an appropriate byte. If @p might be the first * character of the string, you must use g_utf8_find_prev_char instead. * * Return value: a pointer to the found character. **/ gchar * g_utf8_prev_char (const gchar *p) { while (TRUE) { p--; if ((*p & 0xc0) != 0x80) return (gchar *)p; } } /** * g_utf8_strlen: * @p: pointer to the start of a UTF-8 string. * @max: the maximum number of bytes to examine. If @max * is less than 0, then the string is assumed to be * nul-terminated. * * Return value: the length of the string in characters */ gint g_utf8_strlen (const gchar *p, gint max) { int len = 0; const gchar *start = p; /* special case for the empty string */ if (!*p) return 0; /* Note that the test here and the test in the loop differ subtly. In the loop we want to see if we've passed the maximum limit -- for instance if the buffer ends mid-character. Here at the top of the loop we want to see if we've just reached the last byte. */ while (max < 0 || p - start < max) { p = g_utf8_next_char (p); ++len; if (! *p || (max > 0 && p - start > max)) break; } return len; } /** * g_utf8_get_char: * @p: a pointer to unicode character encoded as UTF-8 * * Convert a sequence of bytes encoded as UTF-8 to a unicode character. * * Return value: the resulting character or (gunichar)-1 if @p does * not point to a valid UTF-8 encoded unicode character **/ gunichar g_utf8_get_char (const gchar *p) { int i, mask = 0, len; gunichar result; unsigned char c = (unsigned char) *p; UTF8_COMPUTE (c, mask, len); if (len == -1) return (gunichar)-1; UTF8_GET (result, p, i, mask, len); return result; } /** * g_utf8_offset_to_pointer: * @str: a UTF-8 encoded string * @offset: a character offset within the string. * * Converts from an integer character offset to a pointer to a position * within the string. * * Return value: the resulting pointer **/ gchar * g_utf8_offset_to_pointer (const gchar *str, gint offset) { const gchar *s = str; while (offset--) s = g_utf8_next_char (s); return (gchar *)s; } /** * g_utf8_pointer_to_offset: * @str: a UTF-8 encoded string * @pos: a pointer to a position within @str * * Converts from a pointer to position within a string to a integer * character offset * * Return value: the resulting character offset **/ gint g_utf8_pointer_to_offset (const gchar *str, const gchar *pos) { const gchar *s = str; gint offset = 0; while (s < pos) { s = g_utf8_next_char (s); offset++; } return offset; } gchar * g_utf8_strncpy (gchar *dest, const gchar *src, size_t n) { const gchar *s = src; while (n && *s) { s = g_utf8_next_char(s); n--; } strncpy(dest, src, s - src); dest[s - src] = 0; return dest; } /* unicode_strchr */ /** * g_unichar_to_utf8: * @c: a ISO10646 character code * @outbuf: output buffer, must have at least 6 bytes of space. * If %NULL, the length will be computed and returned * and nothing will be written to @out. * * Convert a single character to utf8 * * Return value: number of bytes written **/ int g_unichar_to_utf8 (gunichar c, gchar *outbuf) { size_t len = 0; int first; int i; if (c < 0x80) { first = 0; len = 1; } else if (c < 0x800) { first = 0xc0; len = 2; } else if (c < 0x10000) { first = 0xe0; len = 3; } else if (c < 0x200000) { first = 0xf0; len = 4; } else if (c < 0x4000000) { first = 0xf8; len = 5; } else { first = 0xfc; len = 6; } if (outbuf) { for (i = len - 1; i > 0; --i) { outbuf[i] = (c & 0x3f) | 0x80; c >>= 6; } outbuf[0] = c | first; } return len; } /** * g_utf8_validate: * @str: a pointer to character data * @max_len: max bytes to validate, or -1 to go until nul * @end: return location for end of valid data * * Validates UTF-8 encoded text. @str is the text to validate; * if @str is nul-terminated, then @max_len can be -1, otherwise * @max_len should be the number of bytes to validate. * If @end is non-NULL, then the end of the valid range * will be stored there (i.e. the address of the first invalid byte * if some bytes were invalid, or the end of the text being validated * otherwise). * * Returns TRUE if all of @str was valid. Many GLib and GTK+ * routines require valid UTF8 as input; * so data read from a file or the network should be checked * with g_utf8_validate() before doing anything else with it. * * Return value: TRUE if the text was valid UTF-8. **/ gboolean g_utf8_validate (const gchar *str, gint max_len, const gchar **end) { const gchar *p; gboolean retval = TRUE; if (end) *end = str; p = str; while ((max_len < 0 || (p - str) < max_len) && *p) { int i, mask = 0, len; gunichar result; unsigned char c = (unsigned char) *p; UTF8_COMPUTE (c, mask, len); if (len == -1) { retval = FALSE; break; } /* check that the expected number of bytes exists in str */ if (max_len >= 0 && ((max_len - (p - str)) < len)) { retval = FALSE; break; } UTF8_GET (result, p, i, mask, len); if (result == (gunichar)-1) { retval = FALSE; break; } p += len; } if (end) *end = p; return retval; }