my $regex = <DATA>;

chomp($regex);
$regex =~ s,^/,,;
$regex =~ s,/$,,;

my $txt = "The target string.";

if ($txt =~ m/$regex/) {
  print "Yes.\n";
}

if ($txt =~ $regex) {
  print "Yes.\n";
}

__DATA__
/\bt\w+t\b/