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 inherited by a sub
class of "IO::Handle". These methods implement the functionality
required for a command based protocol, 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 command. In a scalar
context it returns a single string, in a list context it will return each
line as a separate element
- 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 status 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 direction
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.
- rawdatasend ( DATA )
- Send data to the remote server without performing any conversions.
"DATA" is a scalar.
- read_until_dot ()
- Read data from the remote server until a line consisting 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 filehandle 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 command 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) 1995-2006 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.