package LogMatch;
sub new {
   my $class = shift;
   my %args = @_;

   my $self = {};

   $self->{pre}   = $args{pre}  || 'PREdefault';
   $self->{post}  = $args{post} || 'POSTdefault';
   $self->{term}  = $args{term} || 'TERMdefault';

   bless $self, $class;
}

sub search {
   my $self = shift;
   my $term = shift;

   $term = $self->{term} unless defined $term;
   return qr/$self->{pre}$term$self->{post}/;
}

1;

package main;

my $s1 = LogMatch->new(pre=>'\d\d\d\d',post=>',',term=>'foo');
my $s2 = LogMatch->new;

my @clients = qw( foo bar baz hazmat coz meat );

foreach my $client (@clients) {
   my $regex1 = $s1->search($client);
   my $regex2 = $s2->search($client);
   print "$regex1\t\t$regex2\n";
}