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