Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)NAMENet::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.
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). Com-
munication 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 represen-
tation. 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
perl v5.8.8 2005-02-05 1
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)
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 vari-
able "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 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 (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. This is not
usually required except for some dumb servers, and some
firewall configurations. This can also be set by the
environment variable "FTP_PASSIVE".
perl v5.8.8 2005-02-05 2
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)
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 connec-
tions, 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 suc-
cess. 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 informa-
tion 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
perl v5.8.8 2005-02-05 3
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)
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.
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 transfered
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
mazimum record or page size for files sent with a record
or page structure.
perl v5.8.8 2005-02-05 4
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)
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 transfering data
from a socket, named pipe, or other stream not associ-
ated with a normal file.
ls ( [ DIR ] )
Get a directory listing of "DIR", or the current direc-
tory.
In an array context, returns a list of lines returned
from the server. In a scalar context, returns a refer-
ence to a list.
dir ( [ DIR ] )
Get a directory listing of "DIR", or the current direc-
tory in long format.
In an array context, returns a list of lines returned
from the server. In a scalar context, returns a refer-
ence 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 direc-
tory 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. If an error was encoun-
tered 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
transfered will not be remove automatically.
put_unique ( LOCAL_FILE [, REMOTE_FILE ] )
perl v5.8.8 2005-02-05 5
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)
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
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.
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.
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
perl v5.8.8 2005-02-05 6
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)
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 speci-
fied 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
perl v5.8.8 2005-02-05 7
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)
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 com-
plete 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])
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>
perl v5.8.8 2005-02-05 8
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)
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.
perl v5.8.8 2005-02-05 9
Net::FTP(3p) Perl Programmers Reference Guide Net::FTP(3p)REPORTING BUGS
When reporting bugs/problems please include as much informa-
tion 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.cis.ohio-state.edu/htbin/rfc/rfc959.html
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.
perl v5.8.8 2005-02-05 10