Homework #2

Due Tuesday, September 20, 6:00 PM

Problem 1

Show how to use egrep-style regular expressions to search for

lines that start with a period,
lines that start with a period or comma,
lines that start with a sequence of zero or more blanks followed by a period,
containing an even number (be careful!),
lines containing the words UNCA or UNC-A.

Problem 2

Name an easy way to add the line ``That's all folk's'' to the end of a file.

Problem 3

How can Unix applications determine your default printer? How do you set your default printer?

Problem 4

How can you use the ls command to list files in the order in which they were created, that is, from oldest to newest?

Problem 5

How do you copy the first 50 and last 50 lines of one file into another?

Problem 6

Try out the following two ways of saving a directory into a single file. First, compress all the files of the directory and then tar the compress'ed files. Now, tar the directory and compress the tar'ed file. Which method results in a smaller file?

Problem 7

How do you use the od command to list the bytes of a file as hexadecimal numbers? (No, we didn't study od in class. Read either the book or the man page.)

Problem 8

What option of wc counts the characters in a file?

Problem 9

Describe how wildcard characters can be used in the C shell to match

file names starting with the character 'u',
file names that do not start with a 'u',
file names starting with upper case letters, and
file names that are exactly four characters long.

Problem 10

How do you create a file called ``M*A*S*H''.

Problem 11

Describe how you use the find command to

remove all files whose names end with a tilde (~) character,
print the contents of all files less that 1,024 characters long that haven't been accessed in a year,
generate a list of all directories that are owned by the user with id number 1492, and
generate a list of all files that do not contain the word `Unix'.

Problem 12

Mail your answers to Problems 1 to 11 to Dean Brock.