elinks/src/intl/charsets.c

/* Charsets convertor */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE /* strcasecmp() */
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#if HAVE_LANGINFO_CODESET
#include <langinfo.h>
#endif

#include <ctype.h>
#include <stdlib.h>
#if HAVE_WCTYPE_H
#include <wctype.h>
#endif

#ifdef HAVE_ICONV
#include <errno.h>
#include <iconv.h>
#endif

#include "elinks.h"

#include "document/options.h"
#include "intl/charsets.h"
#include "util/conv.h"
#include "util/error.h"
#include "util/fastfind.h"
#include "util/hash.h"
#include "util/memory.h"
#include "util/string.h"


/* Fix namespace clash on MacOS. */
#define table table_elinks

struct table_entry {
	unsigned char c;
	/* This should in principle be unicode_val_T, but because all
	 * the values currently in codepage.inc fit in 16 bits, we can
	 * as well use uint16_t and halve sizeof(struct table_entry)
	 * from 8 bytes to 4.  Should other characters ever be needed,
	 * unicode_val_T u : 24 might be a possibility, although it
	 * seems a little unportable as bitfields are in principle
	 * restricted to int, which may be 16-bit.  */
	uint16_t u;
};

struct codepage_desc {
	char *name;
	char *const *aliases;

 	/* The Unicode mappings of codepage bytes 0x80...0xFF.
 	 * (0x00...0x7F are assumed to be ASCII in all codepages.)
 	 * Because all current values fit in 16 bits, we store them as
 	 * uint16_t rather than unicode_val_T.  If the codepage does
 	 * not use some byte, then @highhalf maps that byte to 0xFFFF,
 	 * which C code converts to UCS_REPLACEMENT_CHARACTER where
 	 * appropriate.  (U+FFFF is reserved and will never be
 	 * assigned as a character.)  */
	const uint16_t *highhalf;

 	/* If some byte in the codepage corresponds to multiple Unicode
 	 * characters, then the preferred character is in @highhalf
 	 * above, and the rest are listed here in @table.  This table
 	 * is not used for translating from the codepage to Unicode.  */
	const struct table_entry *table;

	/* Whether use iconv for translation */
	unsigned int iconv:1;
};

#include "intl/codepage.inc"
#include "intl/uni_7b.inc"
#include "intl/entity.inc"

/* Declare the external-linkage inline functions defined in this file.
 * Avoid the GCC 4.3.1 warning: `foo' declared inline after being
 * called.  The functions are not declared inline in charsets.h
 * because C99 6.7.4p6 says that every external-linkage function
 * declared inline shall be defined in the same translation unit.
 * The non-inline declarations in charsets.h also make sure that the
 * compiler emits global definitions for the symbols so that the
 * functions can be called from other translation units.  */
NONSTATIC_INLINE char *encode_utf8(unicode_val_T u);
NONSTATIC_INLINE int utf8charlen(const char *p);
NONSTATIC_INLINE unicode_val_T utf8_to_unicode(char **string,
					       const char *end);

static const char strings[256][2] = {
	"\000", "\001", "\002", "\003", "\004", "\005", "\006", "\007",
	"\010", "\011", "\012", "\013", "\014", "\015", "\016", "\017",
	"\020", "\021", "\022", "\023", "\024", "\025", "\026", "\033",
	"\030", "\031", "\032", "\033", "\034", "\035", "\036", "\033",
	"\040", "\041", "\042", "\043", "\044", "\045", "\046", "\047",
	"\050", "\051", "\052", "\053", "\054", "\055", "\056", "\057",
	"\060", "\061", "\062", "\063", "\064", "\065", "\066", "\067",
	"\070", "\071", "\072", "\073", "\074", "\075", "\076", "\077",
	"\100", "\101", "\102", "\103", "\104", "\105", "\106", "\107",
	"\110", "\111", "\112", "\113", "\114", "\115", "\116", "\117",
	"\120", "\121", "\122", "\123", "\124", "\125", "\126", "\127",
	"\130", "\131", "\132", "\133", "\134", "\135", "\136", "\137",
	"\140", "\141", "\142", "\143", "\144", "\145", "\146", "\147",
	"\150", "\151", "\152", "\153", "\154", "\155", "\156", "\157",
	"\160", "\161", "\162", "\163", "\164", "\165", "\166", "\167",
	"\170", "\171", "\172", "\173", "\174", "\175", "\176", "\177",
	"\200", "\201", "\202", "\203", "\204", "\205", "\206", "\207",
	"\210", "\211", "\212", "\213", "\214", "\215", "\216", "\217",
	"\220", "\221", "\222", "\223", "\224", "\225", "\226", "\227",
	"\230", "\231", "\232", "\233", "\234", "\235", "\236", "\237",
	"\240", "\241", "\242", "\243", "\244", "\245", "\246", "\247",
	"\250", "\251", "\252", "\253", "\254", "\255", "\256", "\257",
	"\260", "\261", "\262", "\263", "\264", "\265", "\266", "\267",
	"\270", "\271", "\272", "\273", "\274", "\275", "\276", "\277",
	"\300", "\301", "\302", "\303", "\304", "\305", "\306", "\307",
	"\310", "\311", "\312", "\313", "\314", "\315", "\316", "\317",
	"\320", "\321", "\322", "\323", "\324", "\325", "\326", "\327",
	"\330", "\331", "\332", "\333", "\334", "\335", "\336", "\337",
	"\340", "\341", "\342", "\343", "\344", "\345", "\346", "\347",
	"\350", "\351", "\352", "\353", "\354", "\355", "\356", "\357",
	"\360", "\361", "\362", "\363", "\364", "\365", "\366", "\367",
	"\370", "\371", "\372", "\373", "\374", "\375", "\376", "\377",
};

#ifdef HAVE_ICONV
static iconv_t iconv_cd = (iconv_t)-1;
#endif

static void
free_translation_table(struct conv_table *p)
{
	int i;

	for (i = 0; i < 256; i++)
		if (p[i].t)
			free_translation_table(p[i].u.tbl);

	mem_free(p);
}

/* A string used in conversion tables when there is no correct
 * conversion.  This is compared by address and therefore should be a
 * named array rather than a pointer so that it won't share storage
 * with any other string literal that happens to have the same
 * characters.  */
static const char no_str[] = "*";

static void
new_translation_table(struct conv_table *p)
{
	int i;

	for (i = 0; i < 256; i++)
		if (p[i].t)
			free_translation_table(p[i].u.tbl);
	for (i = 0; i < 128; i++) {
		p[i].t = 0;
		p[i].u.str = strings[i];
	}
	for (; i < 256; i++) {
		p[i].t = 0;
	       	p[i].u.str = no_str;
	}
	p->iconv_cp = -1;
}

#define BIN_SEARCH(table, entry, entries, key, result)					\
{											\
	long _s = 0, _e = (entries) - 1;						\
											\
	while (_s <= _e || !((result) = -1)) {						\
		long _m = (_s + _e) / 2;						\
											\
		if ((table)[_m].entry == (key)) {					\
			(result) = _m;							\
			break;								\
		}									\
		if ((table)[_m].entry > (key)) _e = _m - 1;				\
		if ((table)[_m].entry < (key)) _s = _m + 1;				\
	}										\
}											\

static const unicode_val_T strange_chars[32] = {
0x20ac, 0x0000, 0x002a, 0x0000, 0x201e, 0x2026, 0x2020, 0x2021,
0x005e, 0x2030, 0x0160, 0x003c, 0x0152, 0x0000, 0x0000, 0x0000,
0x0000, 0x0060, 0x0027, 0x0022, 0x0022, 0x002a, 0x2013, 0x2014,
0x007e, 0x2122, 0x0161, 0x003e, 0x0153, 0x0000, 0x0000, 0x0000,
};

#define SYSTEM_CHARSET_FLAG 128
#define is_cp_ptr_utf8(cp_ptr) ((cp_ptr)->aliases == aliases_utf8)

const char *
u2cp_(unicode_val_T u, int to, enum nbsp_mode nbsp_mode)
{
	int j;
	int s;

	if (u < 128) return strings[u];

	if (u < 0xa0) {
		u = strange_chars[u - 0x80];
		if (!u) return NULL;
	}

	to &= ~SYSTEM_CHARSET_FLAG;

	if (is_cp_ptr_utf8(&codepages[to]))
		return encode_utf8(u);

	/* To mark non breaking spaces in non-UTF-8 strings, we use a
	 * special char NBSP_CHAR. */
	if (u == UCS_NO_BREAK_SPACE) {
		if (nbsp_mode == NBSP_MODE_HACK) return NBSP_CHAR_STRING;
		else /* NBSP_MODE_ASCII */ return " ";
	}
	if (u == UCS_SOFT_HYPHEN) return "";

	if (u < 0xFFFF)
		for (j = 0; j < 0x80; j++)
			if (codepages[to].highhalf[j] == u)
				return strings[0x80 + j];
	for (j = 0; codepages[to].table[j].c; j++)
		if (codepages[to].table[j].u == u)
			return strings[codepages[to].table[j].c];

	BIN_SEARCH(unicode_7b, x, N_UNICODE_7B, u, s);
	if (s != -1) return unicode_7b[s].s;

	return no_str;
}

static char utf_buffer[7];

NONSTATIC_INLINE char *
encode_utf8(unicode_val_T u)
{
	memset(utf_buffer, 0, 7);

	if (u < 0x80)
		utf_buffer[0] = u;
	else if (u < 0x800)
		utf_buffer[0] = 0xc0 | ((u >> 6) & 0x1f),
		utf_buffer[1] = 0x80 | (u & 0x3f);
	else if (u < 0x10000)
		utf_buffer[0] = 0xe0 | ((u >> 12) & 0x0f),
		utf_buffer[1] = 0x80 | ((u >> 6) & 0x3f),
		utf_buffer[2] = 0x80 | (u & 0x3f);
	else if (u < 0x200000)
		utf_buffer[0] = 0xf0 | ((u >> 18) & 0x0f),
		utf_buffer[1] = 0x80 | ((u >> 12) & 0x3f),
		utf_buffer[2] = 0x80 | ((u >> 6) & 0x3f),
		utf_buffer[3] = 0x80 | (u & 0x3f);
	else if (u < 0x4000000)
		utf_buffer[0] = 0xf8 | ((u >> 24) & 0x0f),
		utf_buffer[1] = 0x80 | ((u >> 18) & 0x3f),
		utf_buffer[2] = 0x80 | ((u >> 12) & 0x3f),
		utf_buffer[3] = 0x80 | ((u >> 6) & 0x3f),
		utf_buffer[4] = 0x80 | (u & 0x3f);
	else	utf_buffer[0] = 0xfc | ((u >> 30) & 0x01),
		utf_buffer[1] = 0x80 | ((u >> 24) & 0x3f),
		utf_buffer[2] = 0x80 | ((u >> 18) & 0x3f),
		utf_buffer[3] = 0x80 | ((u >> 12) & 0x3f),
		utf_buffer[4] = 0x80 | ((u >> 6) & 0x3f),
		utf_buffer[5] = 0x80 | (u & 0x3f);

	return utf_buffer;
}

/* Number of bytes utf8 character indexed by first byte. Illegal bytes are
 * equal ones and handled different. */
static const char utf8char_len_tab[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, 5,5,5,5,6,6,1,1,
};

#ifdef CONFIG_UTF8
NONSTATIC_INLINE int
utf8charlen(const char *p)
{
	return p ? utf8char_len_tab[(unsigned char)*p] : 0;
}

int
strlen_utf8(char **str)
{
	char *s = *str;
	char *end = strchr((const char *)s, '\0');
	int x;
	int len;

	for (x = 0;; x++, s += len) {
		len = utf8charlen(s);
		if (s + len > end) break;
	}
	*str = s;
	return x;
}

#define utf8_issingle(p) (((p) & 0x80) == 0)
#define utf8_islead(p) (utf8_issingle(p) || ((p) & 0xc0) == 0xc0)

/* Start from @current and move back to @pos char. This pointer return. The
 * most left pointer is @start. */
char *
utf8_prevchar(char *current, int pos, char *start)
{
	if (current == NULL || start == NULL || pos < 0)
		return NULL;
	while (pos > 0 && current != start) {
		current--;
		if (utf8_islead(*current))
			pos--;
	}
	return current;
}

/* Count number of standard terminal cells needed for displaying UTF-8
 * character. */
int
utf8_char2cells(char *utf8_char, char *end)
{
	unicode_val_T u;

	if (end == NULL)
		end = strchr((const char *)utf8_char, '\0');

	if(!utf8_char || !end)
		return -1;

	u = utf8_to_unicode(&utf8_char, end);

	return unicode_to_cell(u);
}

/* Count number of standard terminal cells needed for displaying string
 * with UTF-8 characters. */
int
utf8_ptr2cells(char *string, char *end)
{
	int charlen, cell, cells = 0;

	if (end == NULL)
		end = strchr((const char *)string, '\0');

	if(!string || !end)
		return -1;

	do {
		charlen = utf8charlen(string);
		if (string + charlen > end)
			break;

		cell = utf8_char2cells(string, end);
		if  (cell < 0)
			return -1;

		cells += cell;
		string += charlen;
	} while (1);

	return cells;
}

/* Count number of characters in string. */
int
utf8_ptr2chars(char *string, char *end)
{
	int charlen, chars = 0;

	if (end == NULL)
		end = strchr((const char *)string, '\0');

	if(!string || !end)
		return -1;

	do {
		charlen = utf8charlen(string);
		if (string + charlen > end)
			break;

		chars++;
		string += charlen;
	} while (1);

	return chars;
}

/*
 * Count number of bytes from begining of the string needed for displaying
 * specified number of cells.
 */
int
utf8_cells2bytes(char *string, int max_cells, char *end)
{
	unsigned int bytes = 0, cells = 0;

	assert(max_cells>=0);

	if (end == NULL)
		end = strchr((const char *)string, '\0');

	if(!string || !end)
		return -1;

	do {
		int cell = utf8_char2cells(&string[bytes], end);
		if (cell < 0)
			return -1;

		cells += cell;
		if (cells > max_cells)
			break;

		bytes += utf8charlen(&string[bytes]);

		if (string + bytes > end) {
			bytes = end - string;
			break;
		}
	} while(1);

	return bytes;
}

/* Take @max steps forward from @string in the specified @way, but
 * not going past @end.  Return the resulting address.  Store the
 * number of steps taken to *@count, unless @count is NULL.
 *
 * This assumes the text is valid UTF-8, and @string and @end point to
 * character boundaries.  If not, it doesn't crash but the results may
 * be inconsistent.
 *
 * This function can do some of the same jobs as utf8charlen(),
 * utf8_cells2bytes(), and strlen_utf8().  */
char *
utf8_step_forward(char *string, char *end,
		  int max, enum utf8_step way, int *count)
{
	int steps = 0;
	char *current = string;

	assert(string);
	assert(max >= 0);
	if_assert_failed goto invalid_arg;
	if (end == NULL)
		end = strchr((const char *)string, '\0');

	switch (way) {
	case UTF8_STEP_CHARACTERS:
		while (steps < max && current < end) {
			++current;
			if (utf8_islead(*current))
				++steps;
		}
		break;

	case UTF8_STEP_CELLS_FEWER:
	case UTF8_STEP_CELLS_MORE:
		while (steps < max && current < end) {
			unicode_val_T u;
			char *prev = current;
			int width;

			u = utf8_to_unicode(&current, end);
			if (u == UCS_NO_CHAR) {
				/* Assume the incomplete sequence
				 * costs one cell.  */
				current = end;
				++steps;
				break;
			}

			width = unicode_to_cell(u);
			if (way == UTF8_STEP_CELLS_FEWER
			    && steps + width > max) {
				/* Back off.  */
				current = prev;
				break;
			}
			steps += width;
		}
		break;

	default:
		INTERNAL("impossible enum utf8_step");
	}

invalid_arg:
	if (count)
		*count = steps;
	return current;
}

/* Take @max steps backward from @string in the specified @way, but
 * not going past @start.  Return the resulting address.  Store the
 * number of steps taken to *@count, unless @count is NULL.
 *
 * This assumes the text is valid UTF-8, and @string and @start point
 * to character boundaries.  If not, it doesn't crash but the results
 * may be inconsistent.
 *
 * This function can do some of the same jobs as utf8_prevchar().  */
char *
utf8_step_backward(char *string, char *start,
		   int max, enum utf8_step way, int *count)
{
	int steps = 0;
	char *current = string;

	assert(string);
	assert(start);
	assert(max >= 0);
	if_assert_failed goto invalid_arg;

	switch (way) {
	case UTF8_STEP_CHARACTERS:
		while (steps < max && current > start) {
			--current;
			if (utf8_islead(*current))
				++steps;
		}
		break;

	case UTF8_STEP_CELLS_FEWER:
	case UTF8_STEP_CELLS_MORE:
		while (steps < max) {
			char *prev = current;
			char *look;
			unicode_val_T u;
			int width;

			if (current <= start)
				break;
			do {
				--current;
			} while (current > start && !utf8_islead(*current));

			look = current;
			u = utf8_to_unicode(&look, prev);
			if (u == UCS_NO_CHAR) {
				/* Assume the incomplete sequence
				 * costs one cell.  */
				width = 1;
			} else
				width = unicode_to_cell(u);

			if (way == UTF8_STEP_CELLS_FEWER
			    && steps + width > max) {
				/* Back off.  */
				current = prev;
				break;
			}
			steps += width;
		}
		break;

	default:
		INTERNAL("impossible enum utf8_step");
	}

invalid_arg:
	if (count)
		*count = steps;
	return current;
}

/*
 * Find out number of standard terminal collumns needed for displaying symbol
 * (glyph) which represents Unicode character c.
 *
 * TODO: Use wcwidth when it is available. This seems to require:
 * - Make the configure script check whether <wchar.h> and wcwidth exist.
 * - Define _XOPEN_SOURCE and include <wchar.h>.
 * - Test that __STDC_ISO_10646__ is defined.  (This macro means wchar_t
 *   matches ISO 10646 in all locales.)
 * However, these do not suffice, because wcwidth depends on LC_CTYPE
 * in glibc-2.3.6.  For instance, wcwidth(0xff20) is -1 when LC_CTYPE
 * is "fi_FI.ISO-8859-1" or "C", but 2 when LC_CTYPE is "fi_FI.UTF-8".
 * <features.h> defines __STDC_ISO_10646__ as 200009L, so 0xff20 means
 * U+FF20 FULLWIDTH COMMERCIAL AT regardless of LC_CTYPE; but this
 * character is apparently not supported in all locales.  Why is that?
 * - Perhaps there is standardese that requires supported characters
 *   to be convertable to multibyte form.  Then ELinks could just pick
 *   some UTF-8 locale for its wcwidth purposes.
 * - Perhaps wcwidth can even return different nonnegative values for
 *   the same ISO 10646 character in different locales.  Then ELinks
 *   would have to set LC_CTYPE to match at least the terminal's
 *   charset (which may differ from the LC_CTYPE environment variable,
 *   especially when the master process is serving a slave terminal).
 *   But there is no guarantee that the libc supports all the same
 *   charsets as ELinks does.
 * For now, it seems safest to avoid the potentially locale-dependent
 * libc version of wcwidth, and instead use a hardcoded mapping.
 *
 * @return	2 for double-width glyph, 1 for others.
 * 		0 for unprintable glyphs (like 0x200e: "LEFT-TO-RIGHT MARK")
 */

#if 0
NONSTATIC_INLINE int
unicode_to_cell(unicode_val_T c)
{
	if (c == 0x200e || c == 0x200f)
		return 0;
	if (c >= 0x1100
		&& (c <= 0x115f			/* Hangul Jamo */
		|| c == 0x2329
		|| c == 0x232a
		|| (c >= 0x2e80 && c <= 0xa4cf
			&& c != 0x303f)		/* CJK ... Yi */
		|| (c >= 0xac00 && c <= 0xd7a3)	/* Hangul Syllables */
		|| (c >= 0xf900 && c <= 0xfaff)	/* CJK Compatibility
								Ideographs */
		|| (c >= 0xfe30 && c <= 0xfe6f)	/* CJK Compatibility Forms */
		|| (c >= 0xff00 && c <= 0xff60)	/* Fullwidth Forms */
		|| (c >= 0xffe0 && c <= 0xffe6)
		|| (c >= 0x20000 && c <= 0x2fffd)
		|| (c >= 0x30000 && c <= 0x3fffd)))
		return 2;

	return 1;
}
#endif

/* Fold the case of a Unicode character, so that hotkeys in labels can
 * be compared case-insensitively.  It is unspecified whether the
 * result will be in upper or lower case.  */
unicode_val_T
unicode_fold_label_case(unicode_val_T c)
{
#if __STDC_ISO_10646__ && HAVE_WCTYPE_H
	return towlower(c);
#else  /* !(__STDC_ISO_10646__ && HAVE_WCTYPE_H) */
	/* For now, this supports only ASCII.  It would be possible to
	 * use code generated from CaseFolding.txt of Unicode if the
	 * acknowledgements required by http://www.unicode.org/copyright.html
	 * were added to associated documentation of ELinks.  */
	if (c >= 0x41 && c <= 0x5A)
		return c + 0x20;
	else
		return c;
#endif /* !(__STDC_ISO_10646__ && HAVE_WCTYPE_H) */
}
#endif /* CONFIG_UTF8 */

NONSTATIC_INLINE unicode_val_T
utf8_to_unicode(char **string, const char *end)
{
	unsigned char *str = (unsigned char *)*string;
	unicode_val_T u;
	int length;

	length = utf8char_len_tab[str[0]];

	if (str + length > (const unsigned char *)end) {
		return UCS_NO_CHAR;
	}

	switch (length) {
		case 1:		/* U+0000 to U+007F */
			if (str[0] >= 0x80) {
invalid_utf8:
				++*string;
				return UCS_REPLACEMENT_CHARACTER;
			}
			u = str[0];
			break;
		case 2:		/* U+0080 to U+07FF */
			if ((str[1] & 0xc0) != 0x80)
				goto invalid_utf8;
			u = (str[0] & 0x1f) << 6;
			u += (str[1] & 0x3f);
			if (u < 0x80)
				goto invalid_utf8;
			break;
		case 3:		/* U+0800 to U+FFFF, except surrogates */
			if ((str[1] & 0xc0) != 0x80 || (str[2] & 0xc0) != 0x80)
				goto invalid_utf8;
			u = (str[0] & 0x0f) << 12;
			u += ((str[1] & 0x3f) << 6);
			u += (str[2] & 0x3f);
			if (u < 0x800 || is_utf16_surrogate(u))
				goto invalid_utf8;
			break;
		case 4:		/* U+10000 to U+1FFFFF */
			if ((str[1] & 0xc0) != 0x80 || (str[2] & 0xc0) != 0x80
			    || (str[3] & 0xc0) != 0x80)
				goto invalid_utf8;
			u = (str[0] & 0x0f) << 18;
			u += ((str[1] & 0x3f) << 12);
			u += ((str[2] & 0x3f) << 6);
			u += (str[3] & 0x3f);
			if (u < 0x10000)
				goto invalid_utf8;
			break;
		case 5:		/* U+200000 to U+3FFFFFF */
			if ((str[1] & 0xc0) != 0x80 || (str[2] & 0xc0) != 0x80
			    || (str[3] & 0xc0) != 0x80 || (str[4] & 0xc0) != 0x80)
				goto invalid_utf8;
			u = (str[0] & 0x0f) << 24;
			u += ((str[1] & 0x3f) << 18);
			u += ((str[2] & 0x3f) << 12);
			u += ((str[3] & 0x3f) << 6);
			u += (str[4] & 0x3f);