pids on linux system (no -c option)

Linux doesn't have the -c option for determining which command line statement to display.

http://manpages.ubuntu.com/manpages/quantal/en/man1/ps.1.html

ps -opid,command will output

  PID COMMAND
 8461 flatware sink                                         
 8476 flatware worker 3                                     
 9396 ps -opid,command
29006 -bash

This fixes `flatware clear` which didn't previously work on my linux system and this also stops the warning "Warning: bad ps syntax, perhaps a bogus '-'? See http://procps.sf.net/faq.html" from printing when `ps -c` is called.