Regular expression replace a word by a link

Question

I want to write a regular expression that will replace the word Paris by a link, for only the word is not ready a part of a link.

Example:

    i\'m l         


        

Answer 1

Regexes don't replace. Languages do.

Languages and libraries would also read from the database or file that holds the list of words you care about, and associate a URL with their name. Here's the easiest substitution I can imagine possible my a single regex (perl is used for the replacement syntax.)

s/([a-z-']+)/$1<\/a>/i

Proper names might work better:

s/([A-Z][a-z-']+)/$1<\/a>/gi;

Of course "Baton Rouge" would become two links for:

Baton 
Rouge

In Perl, you can do this:

my $barred_list_of_cities 
    = join( '|'
    , sort { ( length $a <=> $b ) || ( $a cmp $b ) } keys %url_for_city_of
    );
s/($barred_list_of_cities)/$1<\/a>/g;

But again, it's a language that implements a set of operations for regexes, regexes don't do a thing. (In reality, it's such a common application, that I'd be surprised if there isn't a CPAN module out there somewhere that does this, and you just need to load the hash.