thanks all. I went with the following based on your feedback -
use strict;
my @targets = ('10.1.1.1', '10.1.1.2', '10.2.2.1', '10.2.2.2');
my @list = intermix( @targets );
use Data::Dumper;
print Dumper \@list;
sub intermix
{
my @list = @_;
my %hash; # separating hash
my @ret; # returning list
# build hash structure, each similar first 3 octects as key
# array reference w/ IP addresses as values
for (@list) {
push( @{ $hash{ substr($_,0,rindex($_,'.')) } }, $_ );
}
my @keys = keys %hash;
while (@keys)
{
push(@keys, shift(@keys)); # rotate keys
# extract one element, or delete the array ref and try again
my $item = shift @{$hash{ $keys[0] }} || shift @keys && next;
push @ret, $item;
}
return @ret;
}
__END__
$VAR1 = [
'10.1.1.1',
'10.2.2.1',
'10.1.1.2',
'10.2.2.2'
];
This doesn't require a specially defined sequential list type. I'm sorry it doesn't look small and neat though.
Tiago