$re = '/\[\d+\]\s(\w+)\s\|\s(\w+)\s\|\s(\w+)\s\|\s(\S+)\s(\S+)\s\|\s(\S+)\s(\S+)\s\|\s(\S+)\s(\S+)/m';
$str = '[1] weight | width | depth | 5.0 cm | 6.0 mm^2 | 10.12 cm^3';
$subst = "name = $1\nvalue = $4\nunit = $5\n\nname = $2\nvalue = $6\nunit = $7\n\nname = $3\nvalue = $8\nunit = $9";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php