#!/usr/bin/perl --
use strict; use warnings;
Main( @ARGV );
exit( 0 );
sub Main {
    my( $directory ) = @_;
    my $dbh = ...;
    for my $file ( GetFiles( $directory ) ){
        LogFromPcap( $file, $dbh );
    }
    $dbh->disconnect;
}
sub GetFiles {
    use Cwd();
    my $cwd = Cwd::cwd();
    chdir $directory or die $!;
    my @files = glob '*.pcap';
    chdir $cwd;
    return @files;
}
sub LogFromPcap {
    my( $file, $dbh ) = @_;
    ...
}