However, Perl does provide the (?modifier) syntax, for putting the modifiers inside the regex: /(?i)abc/ So, to make this into a full example:

@stuff = ('This is Some text.','This is More text.');
$stext = '/some/i';

($null, $text, $mod) = split(/\//, $stext);

if ($mod and $mod !~ /[^ism]/) {  # a little sanity checking on the mo
+difers
  $mod = "(?$mod)";
} else {
  $mod = '';
}

foreach (grep /$mod$text/, @stuff) {
  print $_, "\n";
}
[download]

Adjust the sanity checking on $mod however you like. BTW, Perl allows (?x) as well as (?ism), but I figured you wouldn't need that here.