use strict; use warnings; my $req = $ENV{QUERY_STRING}; # limits the applicability. Only lowercase file names $req = lc $req; # remove all unwanted characters from the beginning of the string. # In this example, everything except alphanumerics # and underscore is removed. $req =~ s/^[^a-z_0-9]+//; # remove an extension, if any $req =~ s/\.html$//; # default value is the index my $page = "pages/index.html"; # if the page exists, then we use it $page = "pages/$req.html" if -e "pages/$req.html" ;