Solutions

1.      An argument is a word, typically a file name.
	An option is one or more letters preceded by a hyphen that
	affects the behavior of  the command.

2.      $tail filea > filea
	This command line wipes out filea because the shell output
	redirection operator (greater-than sign) recreates filea before
	the tail command runs.  IT DOES NOT PUT THE LAST TEN LINES OF
	FILEA BACK INTO FILEA!

3.	cat fileb filec > file.both

4.  	cat filec fileb > temp; mv temp fileb 

	cat filea filea > temp; mv temp filea 

5.  	Experiment with the noclobber option of bash. 

6.  	sort < roster | lp 

7.  	who | grep mylogname	    

	To display all users but yourself:  who | grep -v mylogname 

8.  	cal | pr -h "John Doe"

9.      $ > answers.0188 < answers cat
	 is the same as 
	$ cat < answers > answers.0188.  
	The shell parses the redirections first.

10.     The noclobber option to the shell only prevents the shell from
	overwriting files with the output redirection greater-than
	operator.  cp and mv don't know about  the noclobber option.
