Please answer the following questions, and place then in a plain text file.  Upon 
completion, email the file to the instructor.  Most convenient would be to just copy this 
file, and place your answers below the questions.


1.  Please briefly describe the following UNIX commands and symbols, including a list of 
    some interesting options for each, if available. The first should help you with the 
    rest:

    man, wget, cat, less, cd, pwd, grep, ls, cp, mv, ssh, |, *, rm, tar, bzip2, 
    pushd, popd, cut, sort, uniq
    
2.  How would one change the mode on a file so that only the owner can read, write, and execute 
    the file, but no other user can do more than read the file?  Give two answers, for each of 
    symbolic and octal values.
    
3.  What would the find command be to find all ordinary files modified within the last 2 
    hours that have an extension of txt?
    
4.  How would you list all the files in a directory that are NOT text files (text files use the .txt 
    extension)?

5.  What are the shell variables "$?" and "$_" for?

6.  Write a program which reads the file located at /nfs/belfry/home/cgi/dmcgrath/cgi-pub/ip_locs.txt.  This
    file is tab delimited.  Print out the second column of this file.  Using Unix pipes on this output, 
    sort, then pull out and count the number of unique entries.
    
EC. Redo number 6 without writing any code.