note 46725 added to function.unpack

I had a situation where I had to unpack a file filled with little-endian order double-floats in a way that would work on either little-endian or big-endian machines. PHP doesn't have a formatting code that will change the byte order of doubles, so I wrote this workaround. <?php /*The following code is a workaround for php's unpack function which does not have the capability of unpacking double precision floats that were packed in the opposite byte order of the current machine. */ function big_endian_unpack ($format, $data) { $ar = unpack ($format, $data); $vals = array_values ($ar); $f = explode ('/', $format); $i = 0; foreach ($f as $f_k => $f_v) { $repeater = intval (substr ($f_v, 1)); if ($repeater == 0) $repeater = 1; if ($f_v{1} == '*') { $repeater = count ($ar) - $i; } if ($f_v{0} != 'd') { $i += $repeater; continue; } $j = $i + $repeater; for ($a = $i; $a < $j; ++$a) { $p = pack ('d',$vals[$i]); $p = strrev ($p); list ($vals[$i]) = array_values (unpack ('d1d', $p)); ++$i; } } $a = 0; foreach ($ar as $ar_k => $ar_v) { $ar[$ar_k] = $vals[$a]; ++$a; } return $ar; } list ($endiantest) = array_values (unpack ('L1L', pack ('V',1))); if ($endiantest != 1) define ('BIG_ENDIAN_MACHINE',1); if (defined ('BIG_ENDIAN_MACHINE')) $unpack_workaround = 'big_endian_unpack'; else $unpack_workaround = 'unpack'; ?> This workaround is used like this: <?php function foo() { global $unpack_workaround; $bar = $unpack_workaround('N7N/V2V/d8d',$my_data); //... } ?> On a little endian machine, $unpack_workaround will simply point to the function unpack. On a big endian machine, it will call the workaround function. Note, this solution only works for doubles. In my project I had no need to check for single precision floats. ---- Manual Page -- http://www.php.net/manual/en/function.unpack.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+46725 Delete -- http://master.php.net/manage/user-notes.php?action=delete+46725&report=yes Reason: bad code -- http://master.php.net/manage/user-notes.php?action=delete+46725&report=yes&reason=bad+code Reason: spam -- http://master.php.net/manage/user-notes.php?action=delete+46725&report=yes&reason=spam Reason: useless example -- http://master.php.net/manage/user-notes.php?action=delete+46725&report=yes&reason=useless+example Reason: contains commercial links -- http://master.php.net/manage/user-notes.php?action=delete+46725&report=yes&reason=contains+commercial+links Reason: useless note -- http://master.php.net/manage/user-notes.php?action=delete+46725&report=yes&reason=useless+note Reject -- http://master.php.net/manage/user-notes.php?action=reject+46725&report=yes Search -- http://master.php.net/manage/user-notes.php