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Net::FTP(3) |
User Contributed Perl Documentation |
Net::FTP(3) |
Net::FTP - FTP Client class
use Net::FTP;
$ftp = Net::FTP->new("some.host.name", Debug => 0)
or die "Cannot connect to some.host.name: $@";
$ftp->login("anonymous",'-anonymous@')
or die "Cannot login ", $ftp->message;
$ftp->cwd("/pub")
or die "Cannot change working directory ", $ftp->message;
$ftp->get("that.file")
or die "get failed ", $ftp->message;
$ftp->quit;
"Net::FTP" is a class implementing a simple
FTP client in Perl as described in RFC959. It provides wrappers for the
commonly used subset of the RFC959 commands. If IO::Socket::IP or
IO::Socket::INET6 is installed it also provides support for IPv6 as defined in
RFC2428. And with IO::Socket::SSL installed it provides support for implicit
FTPS and explicit FTPS as defined in RFC4217.
The Net::FTP class is a subclass of Net::Cmd and (depending on
avaibility) of IO::Socket::IP, IO::Socket::INET6 or IO::Socket::INET.
FTP stands for File Transfer Protocol. It is a way of transferring files between
networked machines. The protocol defines a client (whose commands are provided
by this module) and a server (not implemented in this module). Communication
is always initiated by the client, and the server responds with a message and
a status code (and sometimes with data).
The FTP protocol allows files to be sent to or fetched from the
server. Each transfer involves a local file (on the client) and a
remote file (on the server). In this module, the same file name will
be used for both local and remote if only one is specified. This means that
transferring remote file "/path/to/file"
will try to put that file in
"/path/to/file" locally, unless you
specify a local file name.
The protocol also defines several standard translations
which the file can undergo during transfer. These are ASCII, EBCDIC, binary,
and byte. ASCII is the default type, and indicates that the sender of files
will translate the ends of lines to a standard representation which the
receiver will then translate back into their local representation. EBCDIC
indicates the file being transferred is in EBCDIC format. Binary (also known
as image) format sends the data as a contiguous bit stream. Byte format
transfers the data as bytes, the values of which remain the same regardless
of differences in byte size between the two machines (in theory - in
practice you should only use this if you really know what you're doing).
This class does not support the EBCDIC or byte formats, and will default to
binary instead if they are attempted.
- "new([$host][, %options])"
- This is the constructor for a new Net::FTP object.
$host is the name of the remote host to which an
FTP connection is required.
$host is optional. If
$host is not given then it may instead be passed
as the "Host" option described
below.
%options are passed in a hash like
fashion, using key and value pairs. Possible options are:
Host - FTP host to connect to. It may be a single
scalar, as defined for the "PeerAddr"
option in IO::Socket::INET, or a reference to an array with hosts to try
in turn. The "host" method will return the value which was
used to connect to the host.
Firewall - The name of a machine which acts as an FTP
firewall. This can be overridden by an environment variable
"FTP_FIREWALL". If specified, and the
given host cannot be directly connected to, then the connection is made
to the firewall machine and the string @hostname
is appended to the login identifier. This kind of setup is also referred
to as an ftp proxy.
FirewallType - The type of firewall running on the
machine indicated by Firewall. This can be overridden by an
environment variable
"FTP_FIREWALL_TYPE". For a list of
permissible types, see the description of ftp_firewall_type in
Net::Config.
BlockSize - This is the block size that Net::FTP will
use when doing transfers. (defaults to 10240)
Port - The port number to connect to on the remote
machine for the FTP connection
SSL - If the connection should be done from start with
SSL, contrary to later upgrade with
"starttls".
SSL_* - SSL arguments which will be applied when
upgrading the control or data connection to SSL. You can use SSL
arguments as documented in IO::Socket::SSL, but it will usually use the
right arguments already.
Timeout - Set a timeout value in seconds (defaults to
120)
Debug - debug level (see the debug method in
Net::Cmd)
Passive - If set to a non-zero value then all data
transfers will be done using passive mode. If set to zero then data
transfers will be done using active mode. If the machine is connected to
the Internet directly, both passive and active mode should work equally
well. Behind most firewall and NAT configurations passive mode has a
better chance of working. However, in some rare firewall configurations,
active mode actually works when passive mode doesn't. Some really old
FTP servers might not implement passive transfers. If not specified,
then the transfer mode is set by the environment variable
"FTP_PASSIVE" or if that one is not
set by the settings done by the libnetcfg utility. If none of
these apply then passive mode is used.
Hash - If given a reference to a file handle (e.g.,
"\*STDERR"), print hash marks (#) on
that filehandle every 1024 bytes. This simply invokes the
"hash()" method for you, so that hash
marks are displayed for all transfers. You can, of course, call
"hash()" explicitly whenever you'd
like.
LocalAddr - Local address to use for all socket
connections. This argument will be passed to the super class, i.e.
IO::Socket::INET or IO::Socket::IP.
Domain - Domain to use, i.e. AF_INET or AF_INET6. This
argument will be passed to the IO::Socket super class. This can be used
to enforce IPv4 even with IO::Socket::IP which would default to IPv6.
Family is accepted as alternative name for Domain.
If the constructor fails undef will be returned and an error
message will be in $@
Unless otherwise stated all methods return either a true or false
value, with true meaning that the operation was a success. When a
method states that it returns a value, failure will be returned as
undef or an empty list.
"Net::FTP" inherits from
"Net::Cmd" so methods defined in
"Net::Cmd" may be used to send commands to
the remote FTP server in addition to the methods documented here.
- "login([$login[, $password[, $account]]])"
- Log into the remote FTP server with the given login information. If no
arguments are given then the "Net::FTP"
uses the "Net::Netrc" package to lookup
the login information for the connected host. If no information is found
then a login of anonymous is used. If no password is given and the
login is anonymous then anonymous@ will be used for
password.
If the connection is via a firewall then the
"authorize" method will be called with
no arguments.
- "starttls()"
- Upgrade existing plain connection to SSL. The SSL arguments have to be
given in "new" already because they are
needed for data connections too.
- "stoptls()"
- Downgrade existing SSL connection back to plain. This is needed to work
with some FTP helpers at firewalls, which need to see the PORT and PASV
commands and responses to dynamically open the necessary ports. In this
case "starttls" is usually only done to
protect the authorization.
- "prot($level)"
- Set what type of data channel protection the client and server will be
using. Only $levels "C" (clear) and
"P" (private) are supported.
- "host()"
- Returns the value used by the constructor, and passed to the IO::Socket
super class to connect to the host.
- "account($acct)"
- Set a string identifying the user's account.
- "authorize([$auth[, $resp]])"
- This is a protocol used by some firewall ftp proxies. It is used to
authorise the user to send data out. If both arguments are not specified
then "authorize" uses
"Net::Netrc" to do a lookup.
- "site($args)"
- Send a SITE command to the remote server and wait for a response.
Returns most significant digit of the response code.
- "ascii()"
- Transfer file in ASCII. CRLF translation will be done if required
- "binary()"
- Transfer file in binary mode. No transformation will be done.
Hint: If both server and client machines use the same
line ending for text files, then it will be faster to transfer all files
in binary mode.
- "type([$type])"
- Set or get if files will be transferred in ASCII or binary mode.
- "rename($oldname, $newname)"
- Rename a file on the remote FTP server from
$oldname to $newname. This
is done by sending the RNFR and RNTO commands.
- "delete($filename)"
- Send a request to the server to delete
$filename.
- "cwd([$dir])"
- Attempt to change directory to the directory given in
$dir. If $dir is
"..", the FTP
"CDUP" command is used to attempt to
move up one directory. If no directory is given then an attempt is made to
change the directory to the root directory.
- "cdup()"
- Change directory to the parent of the current directory.
- "passive([$passive])"
- Set or get if data connections will be initiated in passive mode.
- "pwd()"
- Returns the full pathname of the current directory.
- "restart($where)"
- Set the byte offset at which to begin the next data transfer. Net::FTP
simply records this value and uses it when during the next data transfer.
For this reason this method will not return an error, but setting it may
cause a subsequent data transfer to fail.
- "rmdir($dir[, $recurse])"
- Remove the directory with the name $dir. If
$recurse is true then
"rmdir" will attempt to delete
everything inside the directory.
- "mkdir($dir[, $recurse])"
- Create a new directory with the name $dir. If
$recurse is true then
"mkdir" will attempt to create all the
directories in the given path.
Returns the full pathname to the new directory.
- "alloc($size[, $record_size])"
- The alloc command allows you to give the ftp server a hint about the size
of the file about to be transferred using the ALLO ftp command. Some
storage systems use this to make intelligent decisions about how to store
the file. The $size argument represents the size
of the file in bytes. The $record_size argument
indicates a maximum record or page size for files sent with a record or
page structure.
The size of the file will be determined, and sent to the
server automatically for normal files so that this method need only be
called if you are transferring data from a socket, named pipe, or other
stream not associated with a normal file.
- "ls([$dir])"
- Get a directory listing of $dir, or the current
directory.
In an array context, returns a list of lines returned from the
server. In a scalar context, returns a reference to a list.
- "dir([$dir])"
- Get a directory listing of $dir, or the current
directory in long format.
In an array context, returns a list of lines returned from the
server. In a scalar context, returns a reference to a list.
- "get($remote_file[, $local_file[, $where]])"
- Get $remote_file from the server and store
locally. $local_file may be a filename or a
filehandle. If not specified, the file will be stored in the current
directory with the same leafname as the remote file.
If $where is given then the first
$where bytes of the file will not be
transferred, and the remaining bytes will be appended to the local file
if it already exists.
Returns $local_file, or the generated
local file name if $local_file is not given. If
an error was encountered undef is returned.
- "put($local_file[, $remote_file])"
- Put a file on the remote server. $local_file may
be a name or a filehandle. If $local_file is a
filehandle then $remote_file must be specified. If
$remote_file is not specified then the file will
be stored in the current directory with the same leafname as
$local_file.
Returns $remote_file, or the generated
remote filename if $remote_file is not
given.
NOTE: If for some reason the transfer does not complete
and an error is returned then the contents that had been transferred
will not be remove automatically.
- "put_unique($local_file[, $remote_file])"
- Same as put but uses the "STOU" command.
Returns the name of the file on the server.
- "append($local_file[, $remote_file])"
- Same as put but appends to the file on the remote server.
Returns $remote_file, or the generated
remote filename if $remote_file is not
given.
- "unique_name()"
- Returns the name of the last file stored on the server using the
"STOU" command.
- "mdtm($file)"
- Returns the modification time of the given file
- "size($file)"
- Returns the size in bytes for the given file as stored on the remote
server.
NOTE: The size reported is the size of the stored file
on the remote server. If the file is subsequently transferred from the
server in ASCII mode and the remote server and local machine have
different ideas about "End Of Line" then the size of file on
the local machine after transfer may be different.
- "supported($cmd)"
- Returns TRUE if the remote server supports the given command.
- "hash([$filehandle_glob_ref[, $bytes_per_hash_mark]])"
- Called without parameters, or with the first argument false, hash marks
are suppressed. If the first argument is true but not a reference to a
file handle glob, then \*STDERR is used. The second argument is the number
of bytes per hash mark printed, and defaults to 1024. In all cases the
return value is a reference to an array of two: the filehandle glob
reference and the bytes per hash mark.
- "feature($name)"
- Determine if the server supports the specified feature. The return value
is a list of lines the server responded with to describe the options that
it supports for the given feature. If the feature is unsupported then the
empty list is returned.
if ($ftp->feature( 'MDTM' )) {
# Do something
}
if (grep { /\bTLS\b/ } $ftp->feature('AUTH')) {
# Server supports TLS
}
The following methods can return different results depending on
how they are called. If the user explicitly calls either of the
"pasv" or
"port" methods then these methods will
return a true or false value. If the user does not call either
of these methods then the result will be a reference to a
"Net::FTP::dataconn" based object.
- "nlst([$dir])"
- Send an "NLST" command to the server,
with an optional parameter.
- "list([$dir])"
- Same as "nlst" but using the
"LIST" command
- "retr($file)"
- Begin the retrieval of a file called $file from
the remote server.
- "stor($file)"
- Tell the server that you wish to store a file.
$file is the name of the new file that should be
created.
- "stou($file)"
- Same as "stor" but using the
"STOU" command. The name of the unique
file which was created on the server will be available via the
"unique_name" method after the data
connection has been closed.
- "appe($file)"
- Tell the server that we want to append some data to the end of a file
called $file. If this file does not exist then
create it.
If for some reason you want to have complete control over the data
connection, this includes generating it and calling the
"response" method when required, then the
user can use these methods to do so.
However calling these methods only affects the use of the methods
above that can return a data connection. They have no effect on methods
"get",
"put",
"put_unique" and those that do not require
data connections.
- "port([$port])"
- "eprt([$port])"
- Send a "PORT" (IPv4) or
"EPRT" (IPv6) command to the server. If
$port is specified then it is sent to the server.
If not, then a listen socket is created and the correct information sent
to the server.
- "pasv()"
- "epsv()"
- Tell the server to go into passive mode
("pasv" for IPv4,
"epsv" for IPv6). Returns the text that
represents the port on which the server is listening, this text is in a
suitable form to send to another ftp server using the
"port" or
"eprt" method.
The following methods can be used to transfer files between two
remote servers, providing that these two servers can connect directly to
each other.
- "pasv_xfer($src_file, $dest_server[, $dest_file ])"
- This method will do a file transfer between two remote ftp servers. If
$dest_file is omitted then the leaf name of
$src_file will be used.
- "pasv_xfer_unique($src_file, $dest_server[, $dest_file ])"
- Like "pasv_xfer" but the file is stored
on the remote server using the STOU command.
- "pasv_wait($non_pasv_server)"
- This method can be used to wait for a transfer to complete between a
passive server and a non-passive server. The method should be called on
the passive server with the "Net::FTP"
object for the non-passive server passed as an argument.
- "abort()"
- Abort the current data transfer.
- "quit()"
- Send the QUIT command to the remote FTP server and close the socket
connection.
- "quot($cmd[, $args])"
- Send a command, that Net::FTP does not directly support, to the remote
server and wait for a response.
Returns most significant digit of the response code.
WARNING This call should only be used on commands that
do not require data connections. Misuse of this method can hang the
connection.
- "can_inet6()"
- Returns whether we can use IPv6.
- "can_ssl()"
- Returns whether we can use SSL.
Some of the methods defined in "Net::FTP"
return an object which will be derived from the
"Net::FTP::dataconn" class. See
Net::FTP::dataconn for more details.
The following RFC959 commands have not been implemented:
- "SMNT"
- Mount a different file system structure without changing login or
accounting information.
- "HELP"
- Ask the server for "helpful information" (that's what the RFC
says) on the commands it accepts.
- "MODE"
- Specifies transfer mode (stream, block or compressed) for file to be
transferred.
- "SYST"
- Request remote server system identification.
- "STAT"
- Request remote server status.
- "STRU"
- Specifies file structure for file to be transferred.
- "REIN"
- Reinitialize the connection, flushing all I/O and account
information.
For an example of the use of Net::FTP see
- <https://www.csh.rit.edu/~adam/Progs/>
- "autoftp" is a program that can
retrieve, send, or list files via the FTP protocol in a non-interactive
manner.
See
<https://rt.cpan.org/Dist/Display.html?Status=Active&Queue=libnet>.
When reporting bugs/problems please include as much information as possible. It
may be difficult for me to reproduce the problem as almost every setup is
different.
A small script which yields the problem will probably be of help.
It would also be useful if this script was run with the extra options
"Debug => 1" passed to the constructor,
and the output sent with the bug report. If you cannot include a small
script then please include a Debug trace from a run of your program which
does yield the problem.
Net::Netrc, Net::Cmd, IO::Socket::SSL;
ftp(1), ftpd(8);
<https://www.ietf.org/rfc/rfc959.txt>,
<https://www.ietf.org/rfc/rfc2428.txt>,
<https://www.ietf.org/rfc/rfc4217.txt>.
Henry Gabryjelski <henryg@WPI.EDU <mailto:henryg@WPI.EDU>> - for the
suggestion of creating directories recursively.
Nathan Torkington <gnat@frii.com
<mailto:gnat@frii.com>> - for some input on the documentation.
Roderick Schertler <roderick@gate.net
<mailto:roderick@gate.net>> - for various inputs
Graham Barr <gbarr@pobox.com <mailto:gbarr@pobox.com>>.
Steve Hay <shay@cpan.org <mailto:shay@cpan.org>> is
now maintaining libnet as of version 1.22_02.
Copyright (C) 1995-2004 Graham Barr. All rights reserved.
Copyright (C) 2013-2017, 2020 Steve Hay. All rights reserved.
This module is free software; you can redistribute it and/or modify it under the
same terms as Perl itself, i.e. under the terms of either the GNU General
Public License or the Artistic License, as specified in the LICENCE
file.
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