Страницы справочника OS X

Эта страница руководства для  версии 10.9 Mac OS X

Читать страницы руководства

transfer::data::destination(n)            Data transfer facilities            transfer::data::destination(n)



____________________________________________________________________________________________________________

NAME
       transfer::data::destination - Data destination

SYNOPSIS
       package require Tcl  8.4

       package require snit  ?1.0?

       package require transfer::data::destination  ?0.2?

       transfer::data::destination objectName ?options...?

       objectName method ?arg arg ...?

       objectName destroy

       objectName put chunk

       objectName done

       objectName valid msgvar

       objectName receive channel done

____________________________________________________________________________________________________________

DESCRIPTION
       This  package  provides  objects  mainly describing the destination of a data transfer. They are also
       able to initiate the reception of information from a channel into the described destination.

API
       transfer::data::destination objectName ?options...?
              This command creates a new data destination object with an associated Tcl command  whose  name
              is objectName.  This object command is explained in full detail in the sections Object command
              and Object methods. The set of supported options is explained in section Options.

              The object command will be created under the current namespace if the objectName is not  fully
              qualified,  and  in the specified namespace otherwise.  The fully qualified name of the object
              command is returned as the result of the command.


   OBJECT COMMAND
       All objects created by the ::transfer::data::destination command have the following general form:

       objectName method ?arg arg ...?
              The method method and its arg'uments determine the exact behavior of the command.  See section
              Object methods for the detailed specifications.


   OBJECT METHODS
       objectName destroy
              This  method  destroys  the  object.  Doing  so while the object is busy with the reception of
              information from a channel will cause errors later on, when the reception completes and  tries
              to access the now missing data structures of the destroyed object.

       objectName put chunk
              The main receptor method. Saves the received chunk of data into the configured destination. It
              has to be called for each piece of data received.

       objectName done
              The secondary receptor method. Finalizes the receiver. It has to be called when the  receiving
              channel signals EOF. Afterward neither itself nor method put can be called anymore.

       objectName valid msgvar
              This  method checks the configuration of the object for validity. It returns a boolean flag as
              result, whose value is True if the object is valid, and False otherwise. In  the  latter  case
              the  variable whose name is stored in msgvar is set to an error message describing the problem
              found with the configuration. Otherwise this variable is not touched.

       objectName receive channel done
              This method initiates the reception of data from the specified channel. The received data will
              be  stored  into  the configured destination, via calls to the methods put and done.  When the
              reception completes the command prefix done is invoked, with the number of received characters
              appended to it as the sole additional argument.


   OPTIONS
       All  data  destinations support the options listed below. It should be noted that all are semi-exclu-sive, semi-exclusive,
       sive, each specifying a different type of destination and associated information.  If  these  options
       are specified more than once then the last option specified is used to actually configure the object.

       -channel handle
              This option specifies that the destination of the data is a channel, and its associated  argu-ment argument
              ment is the handle of the channel to write the received data to.

       -file path
              This  option specifies that the destination of the data is a file, and its associated argument
              is the path of the file to write the received data to.

       -variable varname
              This option specifies that the destination of the data is a variable, and its associated argu-ment argument
              ment  contains the name of the variable to write the received data to. The variable is assumed
              to be global or namespaced, anchored at the global namespace.

       -progress command
              This option, if specified, defines a command to be invoked for each chunk of  bytes  received,
              allowing the user to monitor the progress of the reception of the data. The callback is always
              invoked with one additional argument, the number of bytes received so far.


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  SF  Trackers  [http://source -
       forge.net/tracker/? group_id=12883].  Please also report any ideas for enhancements you may  have  for
       either package and/or documentation.

KEYWORDS
       channel, copy, data destination, transfer

CATEGORY
       Transfer module

COPYRIGHT
       Copyright (c) 2006-2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>




transfer                                             0.2                      transfer::data::destination(n)