TIMTOWTDI

my %hash1 = ("TEXT", 25,"test",26,"tset",27);
my %hash2 = ("text", 25,"TeSt",24,"xyz",23);
foreach (do {
    my %matcher;
    @matcher{map lc,keys %hash1}=();
    grep exists $matcher{lc $_},keys %hash2;
  }) {
  print "$_ matches\n";
}
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This is similar to jethro's second solution but using map and grep instead of loops. And I made his lchash (matcher here) a local variable so that it's gone when the loop is done.