subfield()

Provides a means to access subfields from a header like Cache-Control, Cookie, and Edge-Control or individual parameters from the query string.

The optional separator character parameter defaults to ,. It can be any one-character constant. For example, ; is a useful separator for extracting parameters from a Set-Cookie field.

This functionality is also achievable by using the : accessor within a variable name. When the subfield is a valueless token (like "private" in the case of Cache-Control: max-age=1200, private), an empty string is returned. The : accessor also works for retrieving variables in a cookie.

This function is not prefixed with the std. namespace.

Format

STRING
subfield(STRING header, STRING fieldname [, STRING separator_character])

Examples

1
2
3
4
5
6
if (subfield(beresp.http.Cache-Control, "private")) {
  return (pass);
}

set beresp.ttl = beresp.http.Cache-Control:max-age;
set beresp.http.Cache-Control:max-age = "1200";

1
2
3
if (subfield(beresp.http.Set-Cookie, "httponly", ";")) {
  #....
}

1
set req.http.value-of-foo = subfield(req.url.qs, "foo", "&");