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transfer::transmitter - Data source

Table Of Contents


package require Tcl 8.5 9
package require snit ?1.0?
package require transfer::copy ?0.2?
package require transfer::data::source ?0.2?
package require transfer::connect ?0.2?
package require transfer::transmitter ?0.2?

transfer::transmitter objectName ?options...?
transfer::transmitter stream channel chan host port ?arg...?
transfer::transmitter stream file path host port ?arg...?
objectName method ?arg arg ...?
objectName destroy
objectName start
objectName busy


This package pulls data sources and connection setup together into a combined object for the transmission of information over a socket. These objects understand all the options from objects created by the packages transfer::data::source and transfer::connect.


Package commands

Object command

All objects created by the ::transfer::transmitter command have the following general form:

Object methods


All transmitter objects support the union of the options supported by their connect and data source components, plus two of their own. See also the documentation for the packages transfer::data::source and transfer::connect.

Secure connections

One way to secure connections made by objects of this package is to require the package tls and then configure the option -socketcmd to force the use of command tls::socket to open the socket.

# Load and initialize tls
package require tls
tls::init -cafile /path/to/ca/cert -keyfile ...

# Create a connector with secure socket setup,
transfer::transmitter T -socketcmd tls::socket ...

TLS Security Considerations

This package uses the TLS package to handle the security for https urls and other socket connections.

Policy decisions like the set of protocols to support and what ciphers to use are not the responsibility of TLS, nor of this package itself however. Such decisions are the responsibility of whichever application is using the package, and are likely influenced by the set of servers the application will talk to as well.

For example, in light of the recent POODLE attack discovered by Google many servers will disable support for the SSLv3 protocol. To handle this change the applications using TLS must be patched, and not this package, nor TLS itself. Such a patch may be as simple as generally activating tls1 support, as shown in the example below.

package require tls
tls::init -tls1 1 ;# forcibly activate support for the TLS1 protocol

... your own application code ...

Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category transfer of the Tcllib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide unified diffs, i.e the output of diff -u.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.


channel, copy, data source, secure, ssl, tls, transfer, transmitter


Transfer module


Copyright © 2006-2009 Andreas Kupries