glib/gutf8.c
Tor Lillqvist 4f9e04c1d7 Use GetACP to get the current ANSI codepage.
2000-12-17  Tor Lillqvist  <tml@iki.fi>

	* gutf8.c (g_utf8_get_charset_internal): (Win32) Use GetACP to get
	the current ANSI codepage.

	* gunicode.h: Add comment that the static string g_get_charset
	sets the parameter to point to should be copied in case the
	charset might be changed later in the program.
2000-12-17 18:43:57 +00:00

617 lines
14 KiB
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 <config.h>
#include <stdlib.h>
#ifdef HAVE_CODESET
#include <langinfo.h>
#endif
#include <string.h>
#include "glib.h"
#ifdef G_OS_WIN32
#include <windows.h>
#endif
#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;
}
static gboolean
g_utf8_get_charset_internal (char **a)
{
char *charset = getenv("CHARSET");
if (charset && a && ! *a)
*a = charset;
if (charset && strstr (charset, "UTF-8"))
return TRUE;
#ifdef HAVE_CODESET
charset = nl_langinfo(CODESET);
if (charset)
{
if (a && ! *a)
*a = charset;
if (strcmp (charset, "UTF-8") == 0)
return TRUE;
}
#endif
#if 0 /* #ifdef _NL_CTYPE_CODESET_NAME */
charset = nl_langinfo (_NL_CTYPE_CODESET_NAME);
if (charset)
{
if (a && ! *a)
*a = charset;
if (strcmp (charset, "UTF-8") == 0)
return TRUE;
}
#endif
#ifdef G_OS_WIN32
if (a && ! *a)
{
static char codepage[10];
sprintf (codepage, "CP%d", GetACP ());
*a = codepage;
/* What about codepage 1200? Is that UTF-8? */
return FALSE;
}
#else
if (a && ! *a)
*a = "US-ASCII";
#endif
/* Assume this for compatibility at present. */
return FALSE;
}
static int utf8_locale_cache = -1;
static char *utf8_charset_cache = NULL;
gboolean
g_get_charset (char **charset)
{
if (utf8_locale_cache != -1)
{
if (charset)
*charset = utf8_charset_cache;
return utf8_locale_cache;
}
utf8_locale_cache = g_utf8_get_charset_internal (&utf8_charset_cache);
if (charset)
*charset = utf8_charset_cache;
return utf8_locale_cache;
}
/* 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_strchr:
* @p: a nul-terminated utf-8 string
* @c: a iso-10646 character/
*
* Find the leftmost occurence of the given iso-10646 character
* in a UTF-8 string.
*
* Return value: NULL if the string does not contain the character, otherwise, a
* a pointer to the start of the leftmost of the character in the string.
**/
gchar *
g_utf8_strchr (const char *p, gunichar c)
{
gchar ch[10];
gint len = g_unichar_to_utf8 (c, ch);
ch[len] = '\0';
return strstr(p, ch);
}
#if 0
/**
* g_utf8_strrchr:
* @p: a nul-terminated utf-8 string
* @c: a iso-10646 character/
*
* Find the rightmost occurence of the given iso-10646 character
* in a UTF-8 string.
*
* Return value: NULL if the string does not contain the character, otherwise, a
* a pointer to the start of the rightmost of the character in the string.
**/
/* This is ifdefed out atm as there is no strrstr function in libc.
*/
gchar *
unicode_strrchr (const char *p, gunichar c)
{
gchar ch[10];
len = g_unichar_to_utf8 (c, ch);
ch[len] = '\0';
return strrstr(p, ch);
}
#endif
/**
* g_utf8_to_ucs4:
* @str: a UTF-8 encoded strnig
* @len: the length of @
*
* Convert a string from UTF-8 to a 32-bit fixed width
* representation as UCS-4.
*
* Return value: a pointer to a newly allocated UCS-4 string.
* This value must be freed with g_free()
**/
gunichar *
g_utf8_to_ucs4 (const char *str, int len)
{
gunichar *result;
gint n_chars, i;
const gchar *p;
n_chars = g_utf8_strlen (str, len);
result = g_new (gunichar, n_chars);
p = str;
for (i=0; i < n_chars; i++)
{
result[i] = g_utf8_get_char (p);
p = g_utf8_next_char (p);
}
return result;
}
/**
* g_ucs4_to_utf8:
* @str: a UCS-4 encoded string
* @len: the length of @
*
* Convert a string from a 32-bit fixed width representation as UCS-4.
* to UTF-8.
*
* Return value: a pointer to a newly allocated UTF-8 string.
* This value must be freed with g_free()
**/
gchar *
g_ucs4_to_utf8 (const gunichar *str, int len)
{
gint result_length;
gchar *result, *p;
gint i;
result_length = 0;
for (i = 0; i < len ; i++)
result_length += g_unichar_to_utf8 (str[i], NULL);
result_length++;
result = g_malloc (result_length + 1);
p = result;
for (i = 0; i < len ; i++)
p += g_unichar_to_utf8 (str[i], p);
*p = '\0';
return result;
}
/**
* 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 <emphasis>require</emphasis> 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;
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)
break;
/* check that the expected number of bytes exists in str */
if (max_len >= 0 &&
((max_len - (p - str)) < len))
break;
UTF8_GET (result, p, i, mask, len);
if (result == (gunichar)-1)
break;
p += len;
}
if (end)
*end = p;
/* See that we covered the entire length if a length was
* passed in, or that we ended on a nul if not
*/
if (max_len >= 0 &&
p != (str + max_len))
return FALSE;
else if (max_len < 0 &&
*p != '\0')
return FALSE;
else
return TRUE;
}