$ perl -wle'
sub glob_limit {
  my ($pat, $max) = @_;
  my $i; print "pattern: $pat";
  while ($val = glob($pat)) {
    print $val;
    last if ++$i == $max;
  }
}
glob_limit("{a,b,c}", 2);
glob_limit("{p,d,q}", 3);
'
pattern: {a,b,c}
a
b
pattern: {p,d,q}
c