Where to get this document

<https://metacpan.org/release/libnet>

How to contribute to this document

<https://rt.cpan.org/Public/Bug/Report.html?Queue=libnet>

Disclaimer

What is libnet ?

Which version of perl do I need ?

What other modules do I need ?

Authen::SASL is required for AUTH support.

IO::Socket::SSL version 2.007 or higher is required for SSL support.

IO::Socket::IP version 0.25 or IO::Socket::INET6 version 2.62 is required for IPv6 support.

What machines support libnet ?

Where can I get the latest libnet release

<https://metacpan.org/release/libnet>

How do I download files from an FTP server ?

    #!/your/path/to/perl

    # a module making life easier

    use Net::FTP;

    # for debugging: $ftp = Net::FTP->new('site','Debug',10);
    # open a connection and log in!

    $ftp = Net::FTP->new('target_site.somewhere.xxx');
    $ftp->login('username','password');

    # set transfer mode to binary

    $ftp->binary();

    # change the directory on the ftp site

    $ftp->cwd('/some/path/to/somewhere/');

    foreach $name ('file1', 'file2', 'file3') {

    # get's arguments are in the following order:
    # ftp server's filename
    # filename to save the transfer to on the local machine
    # can be simply used as get($name) if you want the same name

      $ftp->get($name,$name);
    }

    # ftp done!

    $ftp->quit;

How do I transfer files in binary mode ?

    $ftp->binary;

How can I get the size of a file on a remote FTP server ?

How can I get the modification time of a file on a remote FTP server ?

How can I change the permissions of a file on a remote server ?

    $ftp->quot('site chmod 0777',$filename);

But this is not guaranteed to work.

Can I do a reget operation like the ftp command ?

How do I get a directory listing from an FTP server ?

Changing directory to "" does not fail ?

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

gives

    Net::FTP=GLOB(0x82196d8)>>> CWD /
    Net::FTP=GLOB(0x82196d8)<<< 250 CWD command successful.

I am behind a SOCKS firewall, but the Firewall option does not work ?

To use Net::FTP, or any other module in the libnet distribution, through a SOCKS firewall you must create a socks-ified perl executable by compiling perl with the socks library.

I am behind an FTP proxy firewall, but cannot access machines outside ?

I have heard of one other type of firewall which requires a login to the firewall with an account, then a second login with "user@hostname". You can still use Net::FTP to traverse these firewalls, but a more manual approach must be taken, eg

    $ftp = Net::FTP->new($firewall) or die $@;
    $ftp->login($firewall_user, $firewall_passwd) or die $ftp->message;
    $ftp->login($ext_user . '@' . $ext_host, $ext_passwd) or die $ftp->message.

My ftp proxy firewall does not listen on port 21

If you pass a port number to Net::FTP then it assumes this is the port number of the final destination. By default Net::FTP will always try to connect to the firewall on port 21.

Net::FTP uses IO::Socket to open the connection and IO::Socket allows the port number to be specified as part of the hostname. So this problem can be resolved by either passing a Firewall option like "hostname:1234" or by setting the "ftp_firewall" option in Net::Config to be a string in the same form.

Is it possible to change the file permissions of a file on an FTP server ?

  $ftp->site('chmod','0775',$file);

I have seen scripts call a method message, but cannot find it documented ?

Why does Net::FTP not implement mput and mget methods

sub mput { my($ftp,$pattern) = @_; foreach my $file (glob($pattern)) { $ftp->put($file) or warn $ftp->message; } }

sub mget { my($ftp,$pattern) = @_; foreach my $file ($ftp->ls($pattern)) { $ftp->get($file) or warn $ftp->message; } }

Why can't the part of an Email address after the @ be used as the hostname ?

Why does Net::SMTP not do DNS MX lookups ?

The verify method always returns true ?

    252 Couldn't verify <someone@there> but will attempt delivery anyway

This command will fail only if you pass it an address in a domain the server directly delivers for, and that address does not exist.

How can I debug my scripts that use Net::* modules ?

    #!/your/path/to/perl

    use Net::FTP;

    my $ftp = new Net::FTP($host, Debug => 1);
    $ftp->login('gbarr','password');
    $ftp->quit;

this script would output something like

 Net::FTP: Net::FTP(2.22)
 Net::FTP:   Exporter
 Net::FTP:   Net::Cmd(2.0801)
 Net::FTP:   IO::Socket::INET
 Net::FTP:     IO::Socket(1.1603)
 Net::FTP:       IO::Handle(1.1504)

 Net::FTP=GLOB(0x8152974)<<< 220 imagine FTP server (Version wu-2.4(5) Tue Jul 29 11:17:18 CDT 1997) ready.
 Net::FTP=GLOB(0x8152974)>>> user gbarr
 Net::FTP=GLOB(0x8152974)<<< 331 Password required for gbarr.
 Net::FTP=GLOB(0x8152974)>>> PASS ....
 Net::FTP=GLOB(0x8152974)<<< 230 User gbarr logged in.  Access restrictions apply.
 Net::FTP=GLOB(0x8152974)>>> QUIT
 Net::FTP=GLOB(0x8152974)<<< 221 Goodbye.

The first few lines tell you the modules that Net::FTP uses and their versions, this is useful data to me when a user reports a bug. The last seven lines show the communication with the server. Each line has three parts. The first part is the object itself, this is useful for separating the output if you are using multiple objects. The second part is either "<<<<" to show data coming from the server or "&gt&gt&gt&gt" to show data going to the server. The remainder of the line is the command being sent or response being received.