ydump.ml

open Printf

let license = "\
Copyright (c) 2010-2012 Martin Jambon
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
   derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"

let polycat write_one streaming in_file out_file =
  let ic, fname =
    match in_file with
	`Stdin -> stdin, "<stdin>"
      | `File s -> open_in s, s
  in
  let oc =
    match out_file with
	`Stdout -> stdout
      | `File s -> open_out s
  in
  let finally () =
    if oc != stdout then
      close_out_noerr oc;
    if ic != stdin then
      close_in_noerr ic
  in
  try
    if streaming then
      Stream.iter (write_one oc) (Yojson.Safe.stream_from_channel ~fname ic)
    else
      write_one oc (Yojson.Safe.from_channel ~fname ic);
    finally ();
    true
  with e ->
    finally ();
    eprintf "Error:\n";
    (match e with
	 Yojson.Json_error s ->
	   eprintf "%s\n%!" s
       | e ->
	   eprintf "%s\n%!" (Printexc.to_string e)
    );
    false


let cat output_biniou std compact streaming in_file out_file =
  if not output_biniou then
    let write_one oc x =
      if compact then
	Yojson.Safe.to_channel ~std oc x
      else
	Yojson.Safe.pretty_to_channel ~std oc x;
      output_char oc '\n'
    in
    polycat write_one streaming in_file out_file
      
  else
    let write_one oc x =
      output_string oc (Bi_io.string_of_tree (Yojson_biniou.biniou_of_json x))
    in
    polycat write_one streaming in_file out_file



let parse_cmdline () =
  let out = ref None in
  let std = ref false in
  let compact = ref false in
  let streaming = ref true in
  let output_biniou = ref false in
  let options = [
    "-o", Arg.String (fun s -> out := Some s), 
    "<file>
          Output file";

    "-std", Arg.Set std,
    "
          Convert tuples and variants into standard JSON,
          refuse to print NaN and infinities,
          require the root node to be either an object or an array.";

    "-c", Arg.Set compact,
    "
          Compact output (default: pretty-printed)";

    "-s", Arg.Set streaming,
    "
          Streaming mode: read and write a sequence of JSON values instead of
          just one (default).";

    "-u", Arg.Clear streaming,
    "
          A single JSON record is expected.
          (no longer the default since 1.1.1)";

    "-ob", Arg.Set output_biniou,
    "\
          Experimental";

    "-version",
    Arg.Unit (fun () -> print_endline Yojson.version; exit 0),
    "\
          Print version of yojson and ydump and exit."
  ]
  in
  let files = ref [] in
  let anon_fun s = 
    files := s :: !files
  in
  let msg =
    sprintf "\
JSON pretty-printer based on the Yojson library for OCaml

%s

JSON pretty-printer based on the Yojson library for OCaml

Usage: %s [input file]"
      license Sys.argv.(0)
  in
  Arg.parse options anon_fun msg;
  let in_file =
    match List.rev !files with
	[] -> `Stdin
      | [x] -> `File x
      | _ ->
	  eprintf "Too many input files\n%!";
	  exit 1
  in
  let out_file =
    match !out with
	None -> `Stdout
      | Some x -> `File x
  in
  !output_biniou, !std, !compact, !streaming, in_file, out_file


let () =
  let output_biniou, std, compact, streaming, in_file, out_file =
    parse_cmdline () in
  let success = cat output_biniou std compact streaming in_file out_file in
  if success then
    exit 0
  else
    exit 1