(PECL pecl_http >= 0.10.0)
http_match_request_header — Match any header
$header
   , string $value
   [, bool $match_case = false
  ] )Match an incoming HTTP header.
header
     the header name (case-insensitive)
value
     the header value that should be compared
match_case
     whether the value should be compared case sensitively
   Returns TRUE if header value matches, else FALSE.