#!/usr/bin/perl -w

use strict;
use Net::FTP;

my $host = 'www.ftp.com';
my $user = 'anonymous';
my $pass = 'updatepuller@ftp.com';

my $remote_dir = '/pub/antivirus/NAV/signatures';
my $destination_dir = 'current-sig';
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my @lupd = ();
if(-e "./lastupdate.txt") {
  open(LASTUPDATE,"./lastupdate.txt")
    or die "Error while opening lastupdate.txt ($!)";
  chomp( @lupd = <LASTUPDATE> );
  close(LASTUPDATE);
}
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my %haveit;
@haveit{ @lupd } = (1) x @lupd;

my $ftp = Net::FTP->new($host, Debug => 1);
$ftp->login($user,$pass);
$ftp->type("I");

my @listing = grep /x86\.exe$/i, $ftp->ls($remote_dir);

my @newupdate;
foreach my $file (@listing) {
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  next if $haveit{ $file };
  $ftp->get($file) or next;
  push @newupdate, $file;
}

$ftp->quit;

open(NEWUPDATE,">>./lastupdate.txt")
  or die "Couldn't open lastupdate.txt for appending ($!)";
print NEWUPDATE map "$_\n", @newupdate;
close(NEWUPDATE)
  or die "Closing lastupdate.txt failed ($!)";
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This is great, and really helpful with the hash slice info.

Unfortunately, your version of the script does not appear to compare the file (lastupdate.txt) with the listing on the ftp server. In other words, the program downloads all the files ending in x86.exe and appends the names of the files to the lastupdate.txt file. So...the net gain so far is nada.

I really appreciate your time. Thanks very much!

-Mike

This is strange - I just tested it once again using dummy data and it works for me. Note that the comparison used to determine whether a given file has already been downloaded is (case sensitive) string equality, so preparing lastupdate.txt by hand is likely to fail - it shouldn't ignore the files it added itself though. If this is a problem, you might want to add some kind of canonicalisation step like

  chomp( @lupd = map lc, <LASTUPDATE> );
  ...
  next if $haveit{ lc $file }
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to ignore case.

In any case, I'd recommend you to step it through with the debugger, checking the exact contents of the data structures at any time. This should give enough information to get things working.

The finished product is posted AntiVirus Signature Updater. I tried to give credit to all who helped me. Thank you very much.

Some pointers:

• use strict; it helps!
• `perldoc -q 'quoting.*vars'` (!)
• $lupd is nonsense
• @nupd is nonsense
• $lline is nonsense if you match case-insensitive , see perlop
• And perlre knows your mistake. '$line =~ /x86\.exe/'
• Always, (really always), check the return value of open()! Check close() when you have written to a file.

#!/usr/bin/perl -w

use Strict;
use Net::FTP;

my $host            = 'www.ftp.com';
my $user            = 'anonymous';
my $pass            = 'updatepuller@ftp.com';
my $remote_dir      = '/pub/antivirus/NAV/signatures';
my $destination_dir = 'current-sig';
my $UPDATE_TRACKER  = './lastupdate.txt';


# You should add error checking to make sure you actually make
# a connection to the server

my $ftp = Net::FTP->new($host, Debug => 1);

$ftp->login($user,$pass);

my @listing = $ftp->ls($remote_dir);

foreach (@listing) {

    $_=~s/\r|\n//g;

    if ( /x86\.exe/gi ) {

        my ($response,$errmsg) = do_we_already_have_it($_);

        if ( $response != 1 ) {
        
            # Either we have it or we have an error

            if ($response == -1) {

                # We have an error

                print "Error - $errmsg\n";
                quit_now();            
            
            };
    
        } else {
        
            # We dont have it - grab it        

            ($response,$errmsg) = grab_it($_);

            if ( $response == -1 ) {

                # We have an error

                print "Error - $errmsg\n";
                quit_now();            
            
            };         

        };


    };

};


quit_now();

sub quit_now {

    $ftp->quit;
    exit;
};

sub grab_it {

    # returns  1 if we get the file
    # returns -1 if we dont get the file

    # in its current state it will only return -1 if we cant update
    # the tracker db
        
    my ($remote_file) = @_;

    $ftp->type("I");
    $ftp->get($remote_file);

    # You should add error checking here to make sure you actually
    # get the file !! ( I would but im too tired )

    if ( open(NEWUPDATE,">>$UPDATE_TRACKER") ) {

        print NEWUPDATE "$remote_file\n";
        close(NEWUPDATE);
        return(1);

    } else {

        # Something went wrong return -1 and the error msg
        return(-1,$!);    
    
    };

};


sub do_we_already_have_it {

    # returns  1 if we already have it
    # returns  0 if we dont have it
    # returns -1,error msg if something goes wrong (like permissions)

    my ($check_file) = @_;

    $check_file=~s/\r|\n//g;

    if ( open(LASTUPDATE,$UPDATE_TRACKER) ) { 

        while(<LASTUPDATE>) {

            $_=~s/\r|\n//g;

            if ($_ eq $check_file) {
            
                close(LASTUPDATE);
                return(1);

            };

        };

        close(LASTUPDATE);
        return(0);

    } else {

        # something went wrong - check if the file exists
        # If the file exists then we have some sort of other error
        # that we should probably report back to the client
        # otherwise we simply dont have it yet !
        
        if(-e $UPDATE_TRACKER) { return(-1,$!) };
    
        return(0);
    
    };

};
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First occurance of

if ( $response != 1 ) {
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should have been

if ( $response != 0 ) {
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I blame it on the heat and lack of sleep!