LECTURE 2.  Mon Jan 31:

Processes:

* what are they?  execution of a program
  -- app
  -- background process (daemon)


* what information do they hold?
  -- execution state of a pgm (PC, SP, other regs)
  -- addr space (protected from one anothyer)
  -- code they are running
  -- uid, gid, priority
  -- ability to comm w/other processes via pipes
Fig 2-4:  PROC MANAGEMENT, MEM MANAGEMENT, FILE MANAGEMENT

* Assign2 overview:
  -- fork
  -- nice (-20 = not nice; 20 = very nice; 0 = default)
  -- sig handler 
  -- exec
  -- pipes 

* fork (new process) vs exec (same process)

* uid vs. eiud (euid takes UID of other needed resource, like file)

* why don't parent and child printf's interleave?  (scheduler likes to
  switch when processes are blocked)