$re = '/^.*^(GET.*^error[^\n]*)/ms';
$str = 'first line
second line
GET xxxxx
GET yyyyy
GET zzzzz
Some text
more text
error: this is the first error
GET xxxxx
GET yyyyy
GET zzzzzLAST
Some text
more text
error: this is the last error
last line
';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($matches);
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