How to convert PDF to DOCX on linux

I try to convert pdf file to word, excel and powerpoint.I already tried a lot of command like these:

soffice -env:UserInstallation=file:///$HOME/.libreoffice-headless/ --convert-to docx:"Microsoft Word 2007/2010/2013 XML" file.pdf/usr/bin/soffice --headless --invisible --convert-to docx file.pdfsoffice --infilter="writer_pdf_import" --convert-to doc file.pdf/usr/bin/libreoffice --headless --invisible --convert-to doc file.pdf/usr/bin/soffice --headless --convert-to docx:"Microsoft Word 2007/2010/2013 XML" file.pdfabiword --to=doc file.pdfunoconv -f doc file.pdflowriter --invisible --convert-to doc 'file.pdf'

Always got this error message from soffice/libreoffice/unoconv:

:1: parser error : Document is empty%PDF-1.7

And this one for abiword

Unable to init server: Could not connect: Connection refused** (abiword:6477): WARNING **: clutter failed 0, get a life.Unable to init server: Could not connect: Connection refused

With every command but abiword. I got a doc file with bad character inside.But never get a proper file.

I try to create a file converter so I only want command line method. Don't want to use someone API.

Thank you