You should already be familiar with the following topics:
Regular expression metacharacters
Quantifiers
"Greediness" in regular expressions, aka maximal and minimal matching
Character classes and alternation
The m// matching function
The s/// substitution function
Matching strings other than $_ with the =~ matching operator
Assigning matched strings to lvalues
Patterns and regular expressions are dealt with in depth in chapter 2 of the Camel book, and further information is available in the online Perl documentation by typing perldoc perlre.
The following exercises are intended to refresh your memory of basic regular expressions:
Write a script to search a file for any of the names "Yasser Arafat", "Boris Yeltsin" or "Monica Lewinsky". Print out any lines which contain these names. (Answer: exercises/answers/namesre.pl)
What pattern could be used to match any of: Elvis Presley, Elvis Aron Presley, Elvis A. Presley, Elvis Aaron Presley. (Answer: exercises/answers/elvisre.pl)
What pattern could be used to match a blank line? (Answer: exercises/answers/blanklinere.pl)
What pattern could be used to match an IP address such as 203.20.104.241, where each part of the address is a number from 0 to 255? (Answer: exercises/answers/ipre.pl)