2.20. Insert the Regex Match into the Replacement Text
Perform a search-and-replace that converts URLs into HTML links
that point to the URL, and use the URL as the text for the link. For
this exercise, define a URL as “http:”
and all nonwhitespace characters that follow it. For
Inserting the whole regex match back into the replacement text
is an easy way to insert new text before, after, or around the matched
text, or even between multiple copies of the matched text. Unless
you’re using Python, you don’t have to add any capturing groups to
your regular expression to be able to reuse the overall match.
In Perl, «
$&» is actually a variable.
Perl stores the overall regex match in this variable
after each successful regex match.
$&» syntax to insert the regex
match into the replacement text. Ruby uses backslashes instead of
dollar signs for replacement text tokens, so use «
\&» for the ...