(*

Module: Nsswitch

  Parses /etc/nsswitch.conf

Author: Raphael Pinson <raphink@gmail.com>

About: Reference

  This lens tries to keep as close as possible to `man nsswitch.conf` where possible.

About: Licence

  This file is licensed under the LGPL v2+, like the rest of Augeas.

About: Lens Usage

About: Configuration files

  This lens applies to /etc/nsswitch.conf. See <filter>.

*)

module Nsswitch =

autoload xfm

(************************************************************************

 * Group:                 USEFUL PRIMITIVES

 *************************************************************************)

(* View: comment *)

let comment = Util.comment

(* View: empty *)

let empty = Util.empty

(* View: sep_colon

    The separator for database entries *)

let sep_colon = del /:[ \t]*/ ": "

(* View: database_kw

    The database specification like `passwd', `shadow', or `hosts' *)

let database_kw = Rx.word

(* View: service

    The service specification like `files', `db', or `nis' *)

let service = [ label "service" . store Rx.word ]

(* View: reaction

    The reaction on lookup result like `[NOTFOUND=return]'

    TODO: Use case-insensitive regexps when ticket #147 is fixed.

*)

let reaction =

  let status_kw = /[Ss][Uu][Cc][Cc][Ee][Ss][Ss]/

                | /[Nn][Oo][Tt][Ff][Oo][Uu][Nn][Dd]/

                | /[Uu][Nn][Aa][Vv][Aa][Ii][Ll]/

                | /[Tt][Rr][Yy][Aa][Gg][Aa][Ii][Nn]/

    in let action_kw = /[Rr][Ee][Tt][Uu][Rr][Nn]/

                     | /[Cc][Oo][Nn][Tt][Ii][Nn][Uu][Ee]/

                     | /[Mm][Ee][Rr][Gg][Ee]/

      in let negate = [ Util.del_str "!" . label "negate" ]

        in let reaction_entry = [ label "status" . negate?

                                . store status_kw

                                . Util.del_str "="

                                . [ label "action" . store action_kw ] ]

          in Util.del_str "["

             . [ label "reaction"

               . (Build.opt_list reaction_entry Sep.space) ]

             . Util.del_str "]"

(* View: database *)

let database = 

    [ label "database" . store database_kw

       . sep_colon

       . (Build.opt_list

            (service|reaction)

            Sep.space)

       . Util.comment_or_eol ]

(* View: lns *)

let lns = ( empty | comment | database )*

(* Variable: filter *)

let filter = (incl "/etc/nsswitch.conf")

let xfm = transform lns filter