Net::FTP - FTP Client class
SYNOPSIS
use Net::FTP;
$ftp = Net::FTP->new("some.host.name");
$ftp->login("anonymous","me@here.there");
$ftp->cwd("/pub");
$ftp->get("that.file");
$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.
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
This is the constructor for a new Net::FTP object.
HOST is the name of the remote host to which a FTP
connection is required.
OPTIONS are passed in a hash like fashion, using key
and value pairs. Possible options are:
Firewall - The name of a machine which acts as a 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 refered to as a ftp proxy.
Port - The port number to connect to on the remote
machine for the FTP connection
Timeout - Set a timeout value (defaults to 120)
Debug - debug level (see the debug method in the
Net::Cmd manpage)
Passive - If set to true then all data transfers will
be done using passive mode. This is required for some
dumb servers, and some firewall configurations. This
can also be set by the environment variable
FTP_PASSIVE.
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.
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 the users Email address will be used
for a password.
If the connection is via a firewall then the authorize
method will be called with no arguments.
authorize ( [AUTH [, RESP]])
both arguments are not specified then authorize uses
Net::Netrc to do a lookup.
type (TYPE [, ARGS])
This method will send the TYPE command to the remote
FTP server to change the type of data transfer. The
return value is the previous value.
ascii ([ARGS]) binary([ARGS]) ebcdic([ARGS]) byte([ARGS])
Synonyms for type with the first arguments set
correctly
NOTE ebcdic and byte are not fully supported.
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.
pwd ()
Returns the full pathname of the current directory.
rmdir ( DIR )
Remove the directory with the name DIR.
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.
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
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 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 transfered, 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.
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 transfered 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.
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
transfered 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.
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 a 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
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 the 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
Net::FTP inherits from Net::Cmd so methods defined in
Net::Cmd may be used to send commands to the remote FTP
server.
quot (CMD [,ARGS])
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 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 the timeout
value from the command connection will be used.
Returns the number of bytes written before any <CRLF>
translation.
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:
ALLO
Allocates storage for the file to be transferred.
SMNT
Mount a different file system structure without
changing login or accounting information.
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.
SITE
Request remote server site parameters.
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
the Net::Netrc manpage the Net::Cmd manpage
ftp(1), ftpd(8), RFC 959 http://www.cis.ohio-
state.edu/htbin/rfc/rfc959.html
CREDITS
Henry Gabryjelski <henryg@WPI.EDU> - for the suggestion of
creating directories recursively.
Nathan Torkington <gnat@frii.com> - for some input on the
documentation.
COPYRIGHT
Copyright (c) 1995-1997 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.