Description
array 
unpack ( string format, string data )
     unpack() from binary string into array
     according to format. Returns array
     containing unpacked elements of binary string.
    
     unpack() works slightly different from Perl as
     the unpacked data is stored in an associative array. To
     accomplish this you have to name the different format codes and
     separate them by a slash /.
     
Example 1. unpack() example 
<?php $array = unpack("c2chars/nint", $binarydata); ?>
 |  
 
       The resulting array will contain the entries "chars1",
       "chars2" and "int".
        | 
    | Caution | 
      Note that PHP internally stores integral values as signed. If you
      unpack a large unsigned long and it is of the same size as PHP
      internally stored values the result will be a negative number
      even though unsigned unpacking was specified.
       | 
     See also pack() for an explanation of the format
     codes.