utf8到unicode的一个函数
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2022-06-06 19:49:03
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function utf8_to_unicode($str)
{//来自：http://www.cnblogs.com/niniwzw/archive/2010/12/17/1909534.html
$mState = 0; // cached expected number of octets after the current octet
// until the beginning of the next UTF8 character sequence
$mUcs4 = 0; // cached Unicode character
$mBytes = 1; // cached expected number of octets in the current sequence
$out = array();
$len = strlen($str);
for($i = 0; $i < $len; $i++) {
$in = ord($str{$i});
if ( $mState == 0) {
// When mState is zero we expect either a US-ASCII character or a
// multi-octet sequence.
if (0 == (0x80 & ($in))) {
// US-ASCII, pass straight through.
$out[] = $in;
$mBytes = 1;
} else if (0xC0 == (0xE0 & ($in))) {
// First octet of 2 octet sequence
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 0x1F) << 6;
$mState = 1;
$mBytes = 2;
} else if (0xE0 == (0xF0 & ($in))) {
// First octet of 3 octet sequence
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 0x0F) << 12;
$mState = 2;
$mBytes = 3;
} else if (0xF0 == (0xF8 & ($in))) {
// First octet of 4 octet sequence
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 0x07) << 18;
$mState = 3;
$mBytes = 4;
} else if (0xF8 == (0xFC & ($in))) {
/* First octet of 5 octet sequence.
*
* This is illegal because the encoded codepoint must be either
* (a) not the shortest form or
* (b) outside the Unicode range of 0-0x10FFFF.
* Rather than trying to resynchronize, we will carry on until the end
* of the sequence and let the later error handling code catch it.
*/
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 0x03) << 24;
$mState = 4;
$mBytes = 5;
} else if (0xFC == (0xFE & ($in))) {
// First octet of 6 octet sequence, see comments for 5 octet sequence.
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 1) << 30;
$mState = 5;
$mBytes = 6;
} else {
/* Current octet is neither in the US-ASCII range nor a legal first
* octet of a multi-octet sequence.
*/
trigger_error(
'utf8_to_unicode: Illegal sequence identifier '.
'in UTF-8 at byte '.$i,
E_USER_WARNING
);
return FALSE;
}
} else {
// When mState is non-zero, we expect a continuation of the multi-octet
// sequence
if (0x80 == (0xC0 & ($in))) {
// Legal continuation.
$shift = ($mState - 1) * 6;
$tmp = $in;
$tmp = ($tmp & 0x0000003F) << $shift;
$mUcs4 |= $tmp;
/**
* End of the multi-octet sequence. mUcs4 now contains the final
* Unicode codepoint to be output
*/
if (0 == --$mState) {
/*
* Check for illegal sequences and codepoints.
*/
// From Unicode 3.1, non-shortest form is illegal
if (((2 == $mBytes) && ($mUcs4 < 0x0080)) ||
((3 == $mBytes) && ($mUcs4 < 0x0800)) ||
((4 == $mBytes) && ($mUcs4 < 0x10000)) ||
(4 < $mBytes) ||
// From Unicode 3.2, surrogate characters are illegal
(($mUcs4 & 0xFFFFF800) == 0xD800) ||
// Codepoints outside the Unicode range are illegal
($mUcs4 > 0x10FFFF)) {
trigger_error(
'utf8_to_unicode: Illegal sequence or codepoint '.
'in UTF-8 at byte '.$i,
E_USER_WARNING
);
return FALSE;
}
if (0xFEFF != $mUcs4) {
// BOM is legal but we don't want to output it
$out[] = $mUcs4;
}
//initialize UTF8 cache
$mState = 0;
$mUcs4 = 0;
$mBytes = 1;
}
} else {
/**
*((0xC0 & (*in) != 0x80) && (mState != 0))
* Incomplete multi-octet sequence.
*/
trigger_error(
'utf8_to_unicode: Incomplete multi-octet '.
' sequence in UTF-8 at byte '.$i,
E_USER_WARNING
);
return FALSE;
}
}
}
return $out;
}