Convert .doc to .pdf in command line using Libreoffice

The command would be 

 libreoffice --headless --convert-to pdf test.doc

test.doc is the document which we needed to be converted into pdf and this command will produce test.pdf in the same directory since we haven't specified a output directory.

Apparently this can be used to convert many more types of documents. For example converting a pdf file into odt would work too. 

libreoffice --headless --convert-to odt test.pdf

Its interesting to have a look at the command line options provided by the Libreoffice. 

LibreOffice 3.6

Usage: soffice [options] [documents...]

Options:
--minimized    keep startup bitmap minimized.
--invisible    no startup screen, no default document and no UI.
--norestore    suppress restart/restore after fatal errors.
--quickstart   starts the quickstart service
--nologo       don't show startup screen.
--nolockcheck  don't check for remote instances using the installation
--nodefault    don't start with an empty document
--headless     like invisible but no userinteraction at all.
--help/-h/-?   show this message and exit.
--version      display the version information.
--writer       create new text document.
--calc         create new spreadsheet document.
--draw         create new drawing.
--impress      create new presentation.
--base         create new database.
--math         create new formula.
--global       create new global document.
--web          create new HTML document.
-o            open documents regardless whether they are templates or not.
-n            always open documents as new files (use as template).

--display
      Specify X-Display to use in Unix/X11 versions.
-p
      print the specified documents on the default printer.
--pt
      print the specified documents on the specified printer.
--view
      open the specified documents in viewer-(readonly-)mode.
--show
      open the specified presentation and start it immediately
--accept=
      Specify an UNO connect-string to create an UNO acceptor through which
      other programs can connect to access the API
--unaccept=
      Close an acceptor that was created with -accept=
      Use -unnaccept=all to close all open acceptors
--infilter=
      Force an input filter type if possible
      Eg. -infilter="Calc Office Open XML"
--convert-to output_file_extension[:output_filter_name] [-outdir ouput_dir] files
      Batch convert files.
      If -outdir is not specified then current working dir is used as output_dir.
      Eg. -convert-to pdf *.doc
          -convert-to pdf:writer_pdf_Export -outdir /home/user *.doc
--print-to-file [-printer-name printer_name] [-outdir ouput_dir] files
      Batch print files to file.
      If -outdir is not specified then current working dir is used as output_dir.
      Eg. -print-to-file *.doc
          -print-to-file -printer-name nasty_lowres_printer -outdir /home/user *.doc

Remaining arguments will be treated as filenames or URLs of documents to open.

PS :-
As pointed out by Martin(read comments),  Looks like the above command will not work if the libreoffice application is already running. Thanks for point it out Martin. Does anybody know a work around?