note 37534 deleted from language.types.float by aidan

Note Submitter: rob at xerasystems dot com ---- Hi, A colleague and I are using the socket functions to get data from an Alphaserver running OpenVMS. He writes out a packet of data from the Alpha that contains integers and floats and I pick them up using my PHP script. The two functions below take a 4 byte string that has been parsed from the socket buffer and converts the string to an integer or float. function cvt2int4($intstr,$int4) { // parse the string $int0 = hexdec(bin2hex(substr($intstr,0,1))); $int1 = hexdec(bin2hex(substr($intstr,1,1))); $int2 = hexdec(bin2hex(substr($intstr,2,1))); $int3 = hexdec(bin2hex(substr($intstr,3,1))); // convert to an integer $int4 = $int0*pow(2,0) + $int1*pow(2,8) + $int2*pow(2,16) + $int3*pow(2,24); } function cvt2float4($fltstr,$float4) { // Parse the string $float0 = hexdec(bin2hex(substr($fltstr,0,1))); $float1 = hexdec(bin2hex(substr($fltstr,1,1))); $float2 = hexdec(bin2hex(substr($fltstr,2,1))); $float3 = hexdec(bin2hex(substr($fltstr,3,1))); // Convert to an integer representation $float4 = $float0*pow(2,0) + $float1*pow(2,8) + $float2*pow(2,16) + $float3*pow(2,24); // Get the Sign $sign = ($float4 & 0x80000000) >> 31; // Get the exponent $exp = (($float4 & 0x7F800000) >> 23) - 127; // Get the Mantissa $mantissa = $float4 & 0x007FFFFF; // Calculate the float $sum = 0.0; for ($i=-23;$i<0;$i++) { $value = $mantissa & 1; $sum = $sum + $value*pow(2,$i)*pow(2,$exp); $mantissa = $mantissa >> 1; } $sum = $sum + 1*pow(2,0)*pow(2,$exp); if ($sign == 1) $float4 = $sum*-1; else $float4 = $sum; }