study 2 - 2nd set of study questions

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Vi:
	[[ and ]] for "scrolling" between functions
ctags/vi
   	cntrl-]  - jumping to a tagged function
   	cntrl-t  - popping out of a tagged function
cscope
	tab to move from the results section to the question section
	arrow keys (other keys do this too) for moving around in the sections
	cntrl-d to quit
strace - app for tracing system calls and showing errors
gdb - magic using perror() function call to see errno result -
	there may be other ways to do this.

study questions

1. explain what system calls would be needed (and why they are needed)
for shell redirection of stdout; e.g.,
	ls > file

	here's the start:

	fork() == 0  -- make a child which inherited an open stdout from the
			parent

2. if you have two processes A and B and they behave as follows

	  process A
		open file X
		write 100 bytes to X
		fork B
			write 100 bytes to X

	  now ...

when we reach "now",
what is the value of the file table seek pointer for the file X
	from process A's point of view

what is it for process B

3. what does mmap do.  why is it a problem if you have not done
      munmap yet (e.g., your program crashes).  why is this
      more efficient possibly than straight file i/o?
	  

4. what is the function of the stat call.  how does fstat differ
from stat?