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16 years ago
Planning on sending integer values through as socket, I was surprised to find PHP only supports sending strings. 
I came to the conclusion the only way to do it would be to create a string that would evaluate to the same byte values as the integer I wanted to send. So (after much messing about) I created a couple of functions: one to create this 'string' and one to convert a received value back to an integer.

<?php
//Converts an integer to 'byte array' (string), default to 4 'bytes' (chars)
function int2string($int, $numbytes=4)
{
   $str = "";
   for ($i=0; $i < $numbytes; $i++) {
     $str .= chr($int % 256);
     $int = $int / 256;
   }
   return $str;
}

//Converts a 'byte array' (string) to integer
function string2int($str)
{
   $numbytes = strlen($str);
   $int = 0;
   for ($i=0; $i < $numbytes; $i++) {
     $int += ord($str[$i]) * pow(2, $i * 8);
   }
   return $int;
}

//Example
echo int2string(16705, 2); // 16-bit integer converts to two bytes: 65, 65; which in turn is 'AA'
echo string2int('AA'); //back the other way
?>
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