$re = '/ExceptionName: (?<message>[^\.]+)/m';
$str = '{
MESSAGE : Failed to send
stack_trace : com.abc.xyz.package.ExceptionName: Missing A.
at random.package.w(DummyFile1:45)
at random.package.x(DummyFile2:64)
at random.package.y(DummyFile3:79)
}
{
MESSAGE : Failed to send
stack_trace : com.abc.xyz.package.ExceptionName: Missing B.
at random.package.w(DummyFile1:45)
at random.package.x(DummyFile2:64)
at random.package.y(DummyFile3:79)
}
{
MESSAGE : Failed to send
stack_trace : com.abc.xyz.package.ExceptionName: Missing C.
at random.package.w(DummyFile1:45)
at random.package.x(DummyFile2:64)
at random.package.y(DummyFile3:79)
}';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($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