$re = '/(?xms)
( # group 1
\b explore:
[^\S\r\n]* # optional horizontal whitespaces
[^\n{]* # possible content of the same line
# followed by two possibilities
(?: # the content stops at the end of the line with a ;
; [^\S\r\n]* $
| # or it contains curly brackets and spreads over eventually multiple lines
( # group 2
{
[^{}"]*+ # all that isn\'t curly brackets nor double quotes
(?:
" [^\\\\"]*+ (?: \\\\. [^\\\\"]* )*+ " # contents between quotes
[^{}"]*
|
(?2) # nested curly brackets, recursion in the group 2
[^{}"]*
)*+
}
)
)
)/';
$str = 'explore: character_balance {}
explore: tower_ends {
label: "Tower Results"
join: activity_type {
relationship: many_to_one
type: inner
sql_on: ${activity_type.activity_name}=${wba_fact_activity.activity_name} ;;
}
}
explore: seven11_core_session_start {}';
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