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.tl 'CSCI-E28'Lecture 2'Outline'
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\fBTopics\fR:	Files, System Files, the Manual, Buffering

\fBApproach\fR:	Write our own versions of Unix programs

\fBFeatured Commands\fR:
	who
	cp
	tail

\fBMain Ideas\fR:
	i/o redirection, pipes
	standard directories/files
	the manual tells all
	open, read, write, close
	unix time
	`expensive' operations
	buffered input/output
	

\fBApplications\fR:
	who0 : writing a system utility
	   the manual, the header files

	who1 : reading and displaying data
	   the utmp file
	   open(), read()

	who2 : displaying dates and times
	   localtime(), strftime()
	   
	cp : writing data, creating files
	  creat(), open()
	  write()
	  effect of buffer size:
	    efficiency, system calls, buffering

	who3 : making who more efficient
	  more buffering

	kernel buffering
	  speedier disk access
	
	tail
	  lseek()
	  what it does
	  how it does it