@ 2013-03-22T13:09:01Z <?php
define('INT_SIGNED', 1);
define('INT_LE', 2);
function is32Bit() {
$test = unpack('N', "\xFF\xFF\xFF\xFF");
return current($test) === -1;
}
function unpack_int32($str, $flags = 0) {
$length = strlen($str);
if ($length < 4) {
return false;
} else if ($length > 4) {
$str = substr($str, 0, 4);
}
if ($flags & INT_LE) {
$str = strrev($str);
}
$result = unpack('N', $str);
$result = current($result);
$signBit = (bool) ($result & 0x80000000);
$isSigned = (bool) ($flags & INT_SIGNED);
$is32bit = is32Bit();
var_dump($signBit, $isSigned, $is32bit);
if ($signBit && $isSigned && !$is32bit) {
$result = 0xFFFFFFFF00000000 | $result;
} else if ($signBit && !$isSigned && $is32bit) {
$result = (($result & 0x7FFFFFFF) * 2) + ~$result + 1;
}
return $result;
}
function unpack_int64($str, $flags = 0) {
$length = strlen($str);
if ($length < 8) {
return false;
} else if ($length > 8) {
$str = substr($str, 0, 8);
}
if ($flags & INT_LE) {
$str = strrev($str);
}
$longs = array_values(unpack('NN', substr($str, 0, 4), substr($str, 4, 4)));
$signBit = (bool) ($longs[0] & 0x80000000);
if (!is32Bit()) {
$result = ($longs[0] << 32) | $longs[1];
if ($signBit) {
$result = (($result & 0x7FFFFFFFFFFFFFFF) * 2) + ~$result + 1;
}
}
return $result;
}
var_dump(unpack_int32("\x81\x00\x00\x80", INT_SIGNED | INT_LE));
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Output for 8.1.0 - 8.1.28 , 8.2.0 - 8.2.18 , 8.3.0 - 8.3.6 bool(true)
bool(true)
bool(false)
Deprecated: Implicit conversion from float 1.8446744069414584E+19 to int loses precision in /in/cEj7b on line 32
int(-2147483519)
Output for 4.3.0 - 4.3.11 , 4.4.0 - 4.4.9 , 5.0.0 - 5.0.1 , 5.0.3 - 5.0.5 , 5.1.0 - 5.1.6 , 5.2.0 , 5.2.10 - 5.2.17 , 5.3.0 - 5.3.29 , 5.4.0 - 5.4.45 , 5.5.0 - 5.5.38 , 5.6.0 - 5.6.40 , 7.0.0 - 7.0.33 , 7.1.0 - 7.1.33 , 7.2.0 - 7.2.33 , 7.3.0 - 7.3.33 , 7.4.0 - 7.4.33 , 8.0.0 - 8.0.30 bool(true)
bool(true)
bool(false)
int(-2147483519)
Output for 5.2.1 - 5.2.9 bool(true)
bool(true)
bool(true)
int(-2147483519)
Output for 5.0.2 bool(true)
bool(true)
bool(false)
int(9223372036854775807)
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305.63 ms | 401 KiB | 460 Q