cpdf-source/cpdfattach.ml

305 lines
13 KiB
OCaml

open Pdfutil
open Pdfio
open Cpdferror
(* Remove characters which might not make good filenames. *)
let remove_unsafe_characters encoding s =
if encoding = Cpdfmetadata.UTF8 then Pdftext.utf8_of_pdfdocstring s else (* For @B bookmarks splitting. *)
if encoding = Cpdfmetadata.Raw then s else
let chars =
lose
(function x ->
match x with
'/' | '?' | '<' | '>' | '\\' | ':' | '*' | '|' | '\"' | '^' | '+' | '=' -> true
| x when int_of_char x < 32 || (int_of_char x > 126 && encoding <> Cpdfmetadata.Stripped) -> true
| _ -> false)
(explode s)
in
match chars with
| '.'::more -> implode more
| chars -> implode chars
(* Attaching files *)
let attach_file ?memory keepversion topage pdf file =
let data =
match memory with
Some data -> data
| None ->
let ch = open_in_bin file in
let len = in_channel_length ch in
let stream = mkbytes len in
let i = input_of_channel ch in
setinit i stream 0 len;
close_in ch;
stream
in
let filestream =
Pdf.Stream
(ref (Pdf.Dictionary
[("/Length", Pdf.Integer (bytes_size data));
("/Type", Pdf.Name "/EmbeddedFile");
("/Params",
Pdf.Dictionary
[("/Size", Pdf.Integer (bytes_size data));
("/CheckSum", Pdf.String (Digest.string (string_of_bytes data)))
])],
Pdf.Got data))
in
let filestream_num = Pdf.addobj pdf filestream in
let basename = Pdftext.pdfdocstring_of_utf8 (Filename.basename file) in
let filespec =
Pdf.Dictionary
[("/EF", Pdf.Dictionary ["/F", Pdf.Indirect filestream_num]);
("/F", Pdf.String basename);
("/Type", Pdf.Name "/Filespec");
("/Desc", Pdf.String "");
("/UF", Pdf.String basename)]
in
match topage with
| None ->
(* Look up /Names and /EmbeddedFiles and /Names. *)
let rootdict = Pdf.lookup_obj pdf pdf.Pdf.root in
let namedict =
match Pdf.lookup_direct pdf "/Names" rootdict with
| None -> Pdf.Dictionary []
| Some namedict -> namedict
in
let embeddednamedict =
match Pdf.lookup_direct pdf "/EmbeddedFiles" namedict with
| None -> Pdf.Dictionary []
| Some embeddednamedict -> embeddednamedict
in
let elts =
match Pdf.lookup_direct pdf "/Names" embeddednamedict with
| Some (Pdf.Array elts) -> elts
| _ -> []
in
let filespecobj = Pdf.addobj pdf filespec in
let names' = Pdf.Array (elts @ [Pdf.String basename; Pdf.Indirect filespecobj]) in
let embeddednamedict' = Pdf.add_dict_entry embeddednamedict "/Names" names' in
let namedict' = Pdf.add_dict_entry namedict "/EmbeddedFiles" embeddednamedict' in
let rootdict' = Pdf.add_dict_entry rootdict "/Names" namedict' in
let rootnum = Pdf.addobj pdf rootdict' in
{pdf with
Pdf.minor = if keepversion then pdf.Pdf.minor else max pdf.Pdf.minor 4;
Pdf.root = rootnum;
Pdf.trailerdict =
Pdf.add_dict_entry
pdf.Pdf.trailerdict "/Root" (Pdf.Indirect rootnum)}
| Some pagenumber ->
let pages = Pdfpage.pages_of_pagetree pdf in
if pagenumber < 0 || pagenumber > length pages then error "attach_file: Page not found" else
let page = select pagenumber pages in
let annots =
match Pdf.lookup_direct pdf "/Annots" page.Pdfpage.rest with
| Some (Pdf.Array annots) -> annots
| _ -> []
in
let rect =
let minx, miny, maxx, maxy = Pdf.parse_rectangle pdf page.Pdfpage.mediabox in
Pdf.Array [Pdf.Real 18.; Pdf.Real (maxy -. 45.); Pdf.Real 45.; Pdf.Real (maxy -. 18.)]
in
let filespecobj = Pdf.addobj pdf filespec in
let annot =
Pdf.Dictionary
[("/FS", Pdf.Indirect filespecobj);
("/Subtype", Pdf.Name "/FileAttachment");
("/Contents", Pdf.String basename);
("/Rect", rect)]
in
let annots' = Pdf.Array (annot::annots) in
let page' =
{page with Pdfpage.rest = Pdf.add_dict_entry page.Pdfpage.rest "/Annots" annots'}
in
let pages' = replace_number pagenumber page' pages in
let pdf = Pdfpage.change_pages true pdf pages' in
{pdf with
Pdf.minor = if keepversion then pdf.Pdf.minor else max pdf.Pdf.minor 4}
type attachment =
{name : string;
pagenumber : int;
data : unit -> Pdfio.bytes}
let list_attached_files pdf =
let toplevel =
match Pdf.lookup_direct pdf "/Root" pdf.Pdf.trailerdict with
| None -> []
| Some rootdict ->
match Pdf.lookup_direct pdf "/Names" rootdict with
| None -> []
| Some namedict ->
match Pdf.lookup_direct pdf "/EmbeddedFiles" namedict with
| Some nametree ->
map
(function (x, ef) ->
match Pdf.lookup_direct pdf "/EF" ef with
| Some ((Pdf.Dictionary _) as d) ->
begin match Pdf.lookup_direct pdf "/F" d with
| Some stream ->
{name = Pdftext.utf8_of_pdfdocstring x;
pagenumber = 0;
data =
(fun () ->
try
Pdf.getstream stream;
Pdfcodec.decode_pdfstream pdf stream;
match stream with
Pdf.Stream {contents = (_, Pdf.Got data)} -> data
| _ -> raise Not_found
with
_ -> raise (Pdf.PDFError "could not retreive attachment data"))}
| None -> raise (Pdf.PDFError "/F not found")
end
| _ -> raise (Pdf.PDFError "/EF not found"))
(option_map
(function (Pdf.String s, ef) -> Some (s, ef) | _ -> None)
(Pdf.contents_of_nametree pdf nametree))
| _ -> []
in let pagelevel =
let pages = Pdfpage.pages_of_pagetree pdf in
flatten
(map2
(fun page pagenumber ->
option_map
(function annot ->
match Pdf.lookup_direct pdf "/Subtype" annot with
| Some (Pdf.Name "/FileAttachment") ->
(match Pdf.lookup_direct pdf "/Contents" annot with
| Some (Pdf.String s) ->
begin match Pdf.lookup_direct pdf "/FS" annot with
| Some ((Pdf.Dictionary _) as d) ->
(*Printf.eprintf "%s\n%!" (Pdfwrite.string_of_pdf d);*)
begin match Pdf.lookup_direct pdf "/EF" d with
| Some ((Pdf.Dictionary _) as d) ->
begin match Pdf.lookup_direct pdf "/F" d with
| Some stream ->
Some
{name = Pdftext.utf8_of_pdfdocstring s;
pagenumber = pagenumber;
data =
(fun () ->
try
Pdf.getstream stream;
Pdfcodec.decode_pdfstream pdf stream;
match stream with
Pdf.Stream {contents = (_, Pdf.Got data)} -> data
| _ -> raise Not_found
with
_ -> raise (Pdf.PDFError "could not retreive attachment data"))}
| _ -> raise (Pdf.PDFError "no /F found in attachment")
end
| _ ->
Some
{name = Pdftext.utf8_of_pdfdocstring s;
pagenumber = pagenumber;
data = (fun () -> raise (Pdf.PDFError "no attachment data"))}
end
| _ -> None
end
| _ -> None)
| _ -> None)
(match Pdf.lookup_direct pdf "/Annots" page.Pdfpage.rest with
| Some (Pdf.Array annots) -> annots
| _ -> []))
pages
(indx pages))
in
toplevel @ pagelevel
(* Remove Attached files *)
let remove_attached_files_on_pages pdf =
let remove_from_page page =
{page with Pdfpage.rest =
Pdf.add_dict_entry page.Pdfpage.rest "/Annots"
(Pdf.Array
(option_map
(function annot ->
match Pdf.lookup_direct pdf "/Subtype" annot with
| Some (Pdf.Name "/FileAttachment") -> None
| _ -> Some annot)
(match Pdf.lookup_direct pdf "/Annots" page.Pdfpage.rest with
| Some (Pdf.Array annots) -> annots
| _ -> [])))}
in
Pdfpage.change_pages true pdf (map remove_from_page (Pdfpage.pages_of_pagetree pdf))
let remove_attached_files pdf =
let pdf = remove_attached_files_on_pages pdf in
match Pdf.lookup_direct pdf "/Root" pdf.Pdf.trailerdict with
| None -> pdf
| Some rootdict ->
match Pdf.lookup_direct pdf "/Names" rootdict with
| None -> pdf
| Some namedict ->
let namedict' = Pdf.remove_dict_entry namedict "/EmbeddedFiles" in
let rootdict' = Pdf.add_dict_entry rootdict "/Names" namedict' in
let rootdict'num = Pdf.addobj pdf rootdict' in
{pdf with
Pdf.root =
rootdict'num;
Pdf.trailerdict =
Pdf.add_dict_entry pdf.Pdf.trailerdict "/Root" (Pdf.Indirect rootdict'num)}
let dump_attachment out pdf (_, embeddedfile) =
match Pdf.lookup_direct pdf "/F" embeddedfile with
| Some (Pdf.String s) ->
let efdata =
begin match Pdf.lookup_direct pdf "/EF" embeddedfile with
| Some d ->
let stream =
match Pdf.lookup_direct pdf "/F" d with
| Some s -> s
| None -> error "Bad embedded file stream"
in
Pdfcodec.decode_pdfstream_until_unknown pdf stream;
begin match stream with Pdf.Stream {contents = (_, Pdf.Got b)} -> b | _ -> error "Bad embedded file stream" end
| _ -> error "Bad embedded file stream"
end
in
let s = remove_unsafe_characters Cpdfmetadata.UTF8 s in
let filename = if out = "" then s else out ^ Filename.dir_sep ^ s in
begin try
let fh = open_out_bin filename in
for x = 0 to bytes_size efdata - 1 do output_byte fh (bget efdata x) done;
close_out fh
with
e -> Printf.eprintf "Failed to write attachment to %s\n%!" filename;
end
| _ -> ()
let dump_attached_document pdf out =
let root = Pdf.lookup_obj pdf pdf.Pdf.root in
let names =
match Pdf.lookup_direct pdf "/Names" root with Some n -> n | _ -> Pdf.Dictionary []
in
match Pdf.lookup_direct pdf "/EmbeddedFiles" names with
| Some x ->
iter (dump_attachment out pdf) (Pdf.contents_of_nametree pdf x)
| None -> ()
let dump_attached_page pdf out page =
let annots =
match Pdf.lookup_direct pdf "/Annots" page.Pdfpage.rest with
| Some (Pdf.Array l) -> l
| _ -> []
in
let efannots =
keep
(fun annot ->
match Pdf.lookup_direct pdf "/Subtype" annot with
| Some (Pdf.Name "/FileAttachment") -> true
| _ -> false)
annots
in
let fsannots = option_map (Pdf.lookup_direct pdf "/FS") efannots in
iter (dump_attachment out pdf) (map (fun x -> 0, x) fsannots)
(* Dump both document-level and page-level attached files to file, using their file names *)
let dump_attached_files pdf out =
try
dump_attached_document pdf out;
iter (dump_attached_page pdf out) (Pdfpage.pages_of_pagetree pdf)
with
e -> error (Printf.sprintf "Couldn't dump attached files: %s\n" (Printexc.to_string e))