Como obter estruturas de tabelas de um arquivo .frm usando PHP?

<?php
$fileName = "stops.frm";

// read file into an array of char
//---------------------------------
$handle = fopen($fileName, "rb");
$contents = fread($handle, filesize($fileName));
fclose($handle);
$fileSize=strlen($contents);  // save the filesize fot later printing

// locate the column data near the end of the file
//-------------------------------------------------
$index = 6;    // location of io_size
$io_size_lo = ord($contents[$index]);  
$io_size_hi = ord($contents[$index+1]);
$io_size = $io_size_hi *0x100 + $io_size_lo; // read IO_SIZE

$index = 10;  // location of record length
$rec_len_lo = ord($contents[$index]);
$rec_len_hi = ord($contents[$index+1]);
$rec_len = $rec_len_hi * 0x100 + $rec_len_lo; // read rec_length

// this formula uses io_size and rec_length to get to column data
$colIndex = ( (  (($io_size + $rec_len)/$io_size)   + 1) * $io_size ) + 258;
$colIndex -= 0x3000;   // this is not documented but seems to work!

// find number of columns in the table
//------------------------------------------------- 
echo PHP_EOL."Col data at 0x".dechex($colIndex).PHP_EOL;
$numCols = ord($contents[$colIndex]);

//Extract the column names
//--------------------------------------
$colNameIndex = $colIndex+0x50;   //0X50 by inspection
echo "Col names at 0x".dechex($colNameIndex).PHP_EOL;
$cols=array();
for ($col = 0; $col < $numCols; $col++){
    $nameLen = ord($contents[$colNameIndex++]);          // name length is at ist posn
    $cols[]['ColumnName']= substr($contents,$colNameIndex,$nameLen-1); // read the name
    $colNameIndex+=$nameLen+2;        // skip ahead to next name (2 byte gap after \0)
}
print_r($cols);