php - Regular expression to extract text between braces -

i trying extract text between curly braces in php. e.g

welcome {$user.first_name} {$site} version 1.5. username {$user.username}. reputation @ present {$user.reputation.name}

i have used \{\$(.*?)\} works fine in cases. matches:

• {$user.first_name}
• {$site}
• {$user.username}
• {$user.reputation.name}

but want match text has single or multiple . (dot) within braces. i.e above string should able match only:

• {$user.first_name}
• {$user.username}
• {$user.reputation.name}

please me achieve this! in advance.

you can use

\{\$([^.{}]+(?:\.[^.{}]+)+)\} 

see regex demo

note instead of lazy dot matching .*?, using negated character class [^.{}] matches character other ., { or }. thus, match block not contain ., , still within braces.

the regex breakdown:

• \{\$ - literal {$
• ([^.{}]+(?:\.[^.{}]+)+) - group 1 matching
  • [^.{}]+ - 1 or more characters other ., {, or }
  • (?:\.[^.{}]+)+ - 1 or more (due +) sequences of
    • \. - literal dot
    • [^.{}]+ - 1 or more characters other ., {, or }
• \} - literal }

ideone demo:

$re = '/\{\$([^.{}]+(?:\.[^.{}]+)+)\}/';  $str = "welcome {\$user.first_name} {\$site} version 1.5. username {\$user.username}. reputation @ present {\$user.reputation.name}";  preg_match_all($re, $str, $matches); print_r($matches[1]);