Perl regular expressions
enable you to perform pattern matching by using functions. A regular
expression is a sequence of strings that defines a search
pattern.
For example, suppose
you have the Certadv.NANumbr data set, which contains phone numbers
for the United States, Canada, and Mexico.
By using a regular expression, you can find valid values for Phone. The advantage of using regular expressions is that you can often accomplish in only one Perl regular expression function something that would require a combination ...