$re = '/(?:
#start by finding the initial position of the table start, in order to store the match position for \G
TABLE\n\K|
#after we\'ve found the table head, continue matching using this position. make sure we arent at the beginning of the string
\G(?<!^)
)
#capture the data we\'re interested in
(?:
#make sure there is no \'END\' in the string
(?!END)
#match everything until the line ending
.
)*
#consume the newline at the end of the string
\n/';
$str = '';
$subst = "%\0";
$result = preg_replace($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