The lines in a contact list text file have the format: Last name, first name phone number email address Write a Perl-style regular expression that matches lines that begin with an L, and then include in left-to-right order: the string ", " (comma followed by a space) a phone number formatted with dashes as separators (for example, 415-123-4567). @csm.edu at the end of the line. Perl uses \d to match a decimal digit; .* to match zero or more characters of any type; and \. to match a . (dot in an email address). ^ matches a newline, or the start of a first line in a file, and $ matches the end of a line. The other characters you will need, such as @ and -, simply match themselves. You can test your regular expression with the command grep -p (for Perl) from the Unix command line, using the file regex_test.txt listed below. For example: grep -p "^ .*\.$" regex_test.txt If your regular expression is correct, the grep command will list only the line: Lee, Robin 623-456-7890 rlee@csm.edu

regex_test.txt listing: Lee,Robin 023-456-7890 rlee@csm.edu lee, Robin 123-456-7890 rlee@csm.edu Lee, Robin 223-456-7890 rlee@csm%edu Lee, Robin 323 456-7890 rlee@csm.edu Lee, Robin 423-456-7890 rlee@comcast.net Lee, Robin 523-456-7890 rlee@csm.edu. Lee, Robin 623-456-7890 rlee@csm.edu Young, Chris 723-456-7890 rlee@csm.edu Lee, Robin 823-456-7890 rlee@csm.edu* Lee 93-456-7890 rlee@csm.edu*