CLI for the powerful and free office suite LibreOffice. More information: https://www.libreoffice.org/.
libreoffice --view {{path/to/file1}} {{path/to/file2}}
libreoffice --cat {{path/to/file1}} {{path/to/file2}}
libreoffice --pt {{printer_name}} {{path/to/file1}} {{path/to/file2}}
.doc
files in current directory to pdf:libreoffice --convert-to {{pdf}} {{*.doc}}