IT 441: Network Services Administration
Class #13 Exercise

Complete by: 4/12/2018

Log in to users.cs.umb.edu

• Log in to a Windows machine
  Enter your Unix username as the account name. Then enter your password.
• Run the ssh client
  Use the values in the table below to connect to users.
  
  

  ssh configuration parameter	value
  protocol	ssh
  ssh version	2
  ssh port	22
  host	users.cs.umb.edu
  user name	your unix username
  Authentication method	password

• Enter your password
  A dialog box will appear on the screen into which you must type the password for your Unix account.
• Make sure you are in your home directory
  

                  cd

• Go to your it441 directory

                  cd  it441

• Go to your ex directory
  

                  cd  ex

• Create an ex13 directory
  

                  mkdir  ex13

• Go to your ex13 directory
  

                  cd  ex13

• Execute the script command
  

                  script

• Use your perlsession alias to start the re.pl script.
  

                  perlsession

  (NOTE: If the perlsession alias is not recognized, or if re.pl cannot run, then double-check your Perl configuration, as well as your login shell vs. subshell environments!)

Regexes - The i option and the . Meta-Character

perl>  $string = "foobar" ;

perl>  if ($string =~ /foo/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /Foo/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /BAR/i) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foo.ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /.oo.ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foo..ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

Regexes - The ? Meta-Character

perl>  if ($string =~ /foob?ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foobf?ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foob?far/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foo.?ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foob.?ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foob.?far/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

Regexes - The * Meta-Character

perl>  if ($string =~ /fo*bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foo*bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /fooo*bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foooo*bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foobf*ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foo.*bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /f.*ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

Regexes - The + Meta-Character and Specific Character Counts

perl>  if ($string =~ /fo+bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foo+bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /fo{2}bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /fo{1,3}bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /fooo+bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foob+ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /foo.+bar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /f.+ar/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /fo+.+r/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

Regexes - Special Characters and Cases

perl>  $string = "3.14159" ;

perl>  if ($string =~ /3.14/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /3214/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /3@14/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /3\.14/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ("3214" =~ /3\.14/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /3\.1\d*9/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /3\.1\d+9/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /3\.1\d+/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /3\.[1-5]+9/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

perl>  if ($string =~ /3\.14[13579]+/) { print "Match!\n" ; } else { print "Sorry, no match.\n" ; }

End the Perl Session

perl>  exit

End the script session

Use the exit command. You should then have a file called typescript in your current working directory.