in reply to Why does /i not seem to work

are you aware that the regex object has it's own flags? 
  DB<3> $r="abc|xyz";

  DB<4> $rx=qr($r);

  DB<5> p $rx
(?^u:abc|xyz)

[download]
  DB<6> $rx=qr(/$r/i);   # strike it, see update

  DB<7> p $rx
(?^u:/abc|xyz/i)

[download]

update

Sorry line 6 had the wrong syntax

  DB<27> $rx = qr($r)i;    # or traditionally qr/$r/i

  DB<28> p $rx
(?^ui:abc|xyz)
  DB<29> p "XYZ" =~ $rx
1

[download]

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

In Section Seekers of Perl Wisdom