[Squid external acl scheme - Configuration]
The helper receives lines per the FORMAT specification, and returns OK or ERR indicating the validity of the request.
In addition, any string specified in the referencing acl will also be included in the helper request line, after the specified formats
The optional argument to the acl is included in the call to the helper, for example allowing the same LDAP group lookup helper external_acl_type definition to be used to match a number of different groups in different ACL's.
The helper receives lines per the above format specification, and returns lines starting with OK or ERR indicating the validity of the request and optionally followed by additional keywords with more details.
General result syntax:
OK/ERR keyword=value ...
Keyword values need to be enclosed in quotes if they may contain whitespace, or the whitespace escaped using \. Any quotes or \ characters within the keyword value must be \ escaped.