NAME¶
Net::FTP - FTP Client class
SYNOPSIS¶
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;
DESCRIPTION¶
"Net::FTP" is a class implementing a simple FTP client in Perl as
described in RFC959. It provides wrappers for a subset of the RFC959 commands.
The Net::FTP class is a subclass of Net::Cmd and IO::Socket::INET.
OVERVIEW¶
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).
CONSTRUCTOR¶
- 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
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 IO::Socket::INET
If the constructor fails undef will be returned and an error message will be
in $@
METHODS¶
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.
- 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.
- 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 ] )
- Send a "PORT" 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 ()
- Tell the server to go into passive mode. Returns the text that represents
the port on which the server is listening, this text is in a suitable form
to sent to another ftp server using the "port" 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.
Methods for the adventurous¶
- 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.
THE dataconn CLASS¶
Some of the methods defined in "Net::FTP" return an object which will
be derived from this class.The dataconn class itself is derived from the
"IO::Socket::INET" class, so any normal IO operations can be
performed. However the following methods are defined in the dataconn class and
IO should be performed using these.
- read ( BUFFER, SIZE [, TIMEOUT ] )
- Read "SIZE" bytes of data from the server and place it into
"BUFFER", also performing any <CRLF> translation
necessary. "TIMEOUT" is optional, if not given, the timeout
value from the command connection will be used.
Returns the number of bytes read before any <CRLF> translation.
- write ( BUFFER, SIZE [, TIMEOUT ] )
- Write "SIZE" bytes of data from "BUFFER" to the
server, also performing any <CRLF> translation necessary.
"TIMEOUT" is optional, if not given, the timeout value from the
command connection will be used.
Returns the number of bytes written before any <CRLF>
translation.
- bytes_read ()
- Returns the number of bytes read so far.
- abort ()
- Abort the current data transfer.
- close ()
- Close the data connection and get a response from the FTP server. Returns
true if the connection was closed successfully and the first digit
of the response from the server was a '2'.
UNIMPLEMENTED¶
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.
REPORTING BUGS¶
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.
AUTHOR¶
Graham Barr <gbarr@pobox.com>
SEE ALSO¶
Net::Netrc Net::Cmd
ftp(1),
ftpd(8), RFC 959
http://www.ietf.org/rfc/rfc959.txt
USE EXAMPLES¶
For an example of the use of Net::FTP see
- http://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.
CREDITS¶
Henry Gabryjelski <henryg@WPI.EDU> - for the suggestion of creating
directories recursively.
Nathan Torkington <gnat@frii.com> - for some input on the documentation.
Roderick Schertler <roderick@gate.net> - for various inputs
COPYRIGHT¶
Copyright (c) 1995-2004 Graham Barr. All rights reserved. This program is free
software; you can redistribute it and/or modify it under the same terms as
Perl itself.