package genspio

Typed command-line parsing for your shell scripts, à la Printf.scanf.

Use this module like OCaml's Printf.scanf function.

• Build a command-line “format specification” using the Arg module.
• Call the parse function with an appropriately typed function.

Example: Here is a potential argument specification for a shell script that downloads and unarchives them (see also "src/test/examples.ml").

let cli_spec =
  Command_line.Arg.(
    string
      ~doc:"The URL to the stuff" ["-u"; "--url"]
      ~default:no_value
    & flag ["-d"; "--remove-intermediary-files"]
        ~doc:"Remove intermediary files."
    & string ["-f"; "--local-filename"]
      ~doc:"Override the downloaded file-name"
      ~default:no_value
    & string ["-t"; "--tmp-dir"]
      ~doc:"Use <dir> as temp-dir"
      ~default:(Genspio.EDSL.string "/tmp/genspio-downloader-tmpdir")
    & usage "Download archives and decrypt/unarchive them.\n\
             ./downloader -u URL [-c] [-f <file>] [-t <tmpdir>]"
  ) in
(*
   `cli_spec` has type:

    (string Genspio.EDSL.t ->
     bool Genspio.EDSL.t ->
     string Genspio.EDSL.t -> string Genspio.EDSL.t -> unit Genspio.EDSL.t,
     unit Genspio.EDSL.t)
    Genspio.EDSL.Command_line.cli_options

    so the action function (the second argument to parse) must have type:

    anon:string list Genspio.EDSL.t ->
    string Genspio.EDSL.t ->
    bool Genspio.EDSL.t ->
    string Genspio.EDSL.t ->
    string Genspio.EDSL.t ->
    unit Genspio.EDSL.t
*)
Command_line.parse cli_spec
  (fun ~anon url all_in_tmp filename_ov tmp_dir ->
     (*
        ...
        your code
        ...
     *)