net::cmd(3)
NAME
Net::Cmd - Network Command class (as used by FTP, SMTP
etc)
SYNOPSIS
use Net::Cmd; @ISA = qw(Net::Cmd);
DESCRIPTION
"Net::Cmd" is a collection of methods that can be inher
ited by a sub class of "IO::Handle". These methods imple
ment the functionality required for a command based proto
col, for example FTP and SMTP.
USER METHODS
These methods provide a user interface to the "Net::Cmd"
object.
- debug ( VALUE )
- Set the level of debug information for this object. If
"VALUE" is not given then the current state is
returned. Otherwise the state is changed to "VALUE"
and the previous state returned. - Different packages may implement different levels of
debug but a non-zero value results in copies of all
commands and responses also being sent to STDERR. - If "VALUE" is "undef" then the debug level will be set
to the default debug level for the class. - This method can also be called as a static method to
set/get the default debug level for a given class. - message ()
- Returns the text message returned from the last com
mand - code ()
- Returns the 3-digit code from the last command. If a
command is pending then the value 0 is returned - ok ()
- Returns non-zero if the last code value was greater
than zero and less than 400. This holds true for most
command servers. Servers where this does not hold may
override this method. - status ()
- Returns the most significant digit of the current sta
tus code. If a command is pending then "CMD_PENDING"
is returned. - datasend ( DATA )
- Send data to the remote server, converting LF to CRLF.
Any line starting with a '.' will be prefixed with
another '.'. "DATA" may be an array or a reference to
an array. - dataend ()
- End the sending of data to the remote server. This is
done by ensuring that the data already sent ends with
CRLF then sending '.CRLF' to end the transmission.
Once this data has been sent "dataend" calls
"response" and returns true if "response" returns
CMD_OK.
CLASS METHODS
These methods are not intended to be called by the user,
but used or over-ridden by a sub-class of "Net::Cmd"
- debug_print ( DIR, TEXT )
- Print debugging information. "DIR" denotes the direc
tion true being data being sent to the server. Calls
"debug_text" before printing to STDERR. - debug_text ( TEXT )
- This method is called to print debugging information.
TEXT is the text being sent. The method should return
the text to be printed - This is primarily meant for the use of modules such as
FTP where passwords are sent, but we do not want to
display them in the debugging information. - command ( CMD [, ARGS, ... ])
- Send a command to the command server. All arguments a
first joined with a space character and CRLF is
appended, this string is then sent to the command
server. - Returns undef upon failure
- unsupported ()
- Sets the status code to 580 and the response text to
'Unsupported command'. Returns zero. - response ()
- Obtain a response from the server. Upon success the
most significant digit of the status code is returned.
Upon failure, timeout etc., undef is returned. - parse_response ( TEXT )
- This method is called by "response" as a method with
one argument. It should return an array of 2 values,
the 3-digit status code and a flag which is true when
this is part of a multi-line response and this line is
not the list. - getline ()
- Retrieve one line, delimited by CRLF, from the remote
server. Returns undef upon failure. - NOTE: If you do use this method for any reason, please
remember to add some "debug_print" calls into your
method. - ungetline ( TEXT )
- Unget a line of text from the server.
- read_until_dot ()
- Read data from the remote server until a line consist
ing of a single '.'. Any lines starting with '..'
will have one of the '.'s removed. - Returns a reference to a list containing the lines, or
undef upon failure. - tied_fh ()
- Returns a filehandle tied to the Net::Cmd object.
After issuing a command, you may read from this file
handle using read() or <>. The filehandle will return EOF when the final dot is encountered. Similarly, you
may write to the filehandle in order to send data to
the server after issuing a commmand that expects data
to be written. - See the Net::POP3 and Net::SMTP modules for examples
of this.
EXPORTS
"Net::Cmd" exports six subroutines, five of these,
"CMD_INFO", "CMD_OK", "CMD_MORE", "CMD_REJECT" and
"CMD_ERROR", correspond to possible results of "response"
and "status". The sixth is "CMD_PENDING".
AUTHOR
Graham Barr <gbarr@pobox.com>
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.
- $Id: //depot/libnet/Net/Cmd.pm#28 $