Hello, on Linux it goes like so:
$ dcraw -w -T *.PEF
This creates 8-bit tiff files. If you want 16-bit files, says this:
$ dcraw -w -T -6 *.PEF
More about converting raws using dcraw is here:
https://paulsphotopalace.wordpress.com/dcraw-2/
You might want to throw a look at the Handy section as well.