$re = '/Igroup Name:\s+((?:[\w-]+,\s*)*[\w-]+)/m';
$str = 'Address: c8245A626
AliasName: eSrb002359_f1
Igroup Name: rtvclar002359, unjlclar002358-9,
cokeclar00RCB_FC
Protocol: REST';
preg_match_all($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