Ubuntu Manpage: transfer::copy - Data transfer foundation

NAME

       transfer::copy - Data transfer foundation

SYNOPSIS

       package require Tcl  8.4

       package require transfer::copy  ?0.2?

       transfer::copy::do chan|string data outchannel ?options...?

       transfer::copy::chan channel outchannel ?options...?

       transfer::copy::string string outchannel ?options...?

       transfer::copy::doChan channel outchannel optvar

       transfer::copy::doString string outchannel optvar

       transfer::copy::options outchannel optionlist optvar

_________________________________________________________________

DESCRIPTION

       This  package  provides a number of commands for the asynchronous of information contained
       in either a string or channel. The main point of this package is that  the  commands  here
       provide  a  nicer  callback  API  than  the builtin command fcopy, making the use of these
       facilities simpler than the builtin.

API

transfer::copy::do chan|string data outchannel ?options...?
This command transfers the information in data to the outchannel, according to the
options. The type of the information in data is determined by the first argument.

The options available to this command are the same as are available to the command
transfer::copy::options, and explained there.

chan The argument data contains the handle of a channel and the actual
infomration to transfer is read from that channel.

string The argument data contains a string and this is the information to be
transfered.

transfer::copy::chan channel outchannel ?options...?
This command is a shorter and more direct form for the command transfer::copy::do
chan.

transfer::copy::string string outchannel ?options...?
This command is a shorter and more direct form for the command transfer::copy::do
string.

transfer::copy::doChan channel outchannel optvar
This command is an alternate form of transfer::copy::chan which reads its options
out of the array variable named by optvar instead of from a variable length
argument list.

transfer::copy::doString string outchannel optvar
This command is an alternate form of transfer::copy::string which reads its options
out of the array variable named by optvar instead of from a variable length
argument list.

transfer::copy::options outchannel optionlist optvar
This command is the option processor used by all the commands above which read
their options from a variable length argument list. It first reads default settings
from the channel handle outchannel, then processes the list of options in
optionlist, at last stores the results in the array variable named by optvar. The
contents of that variable are in a format which is directly understood by all the
commands above which read their options out of an array variable.

The recognized options are:

-blocksize int
This option specifies the size of the chunks to transfer in one operation.
It is optional and defaults to the value of -buffersize as configured for
the output channel.

If specified its value has to be an integer number greater than zero.

-command commandprefix
This option specifies the completion callback of the operation. This option
has to be specified. An error will be thrown if it is not, or if the empty
list was specified as argument to it.

Its value has to be a command prefix, i.e. a list whose first word is the
command to execute, followed by words containing fixed arguments. When the
callback is invoked one or two additional arguments are appended to the
prefix. The first argument is the number of bytes which were transfered. The
optional second argument is an error message and added if and only if an
error occured during the the transfer.

-progress commandprefix
This option specifies the progress callback of the operation. It is optional
and defaults to the empty list. This last possibility signals that no
feedback was asked for and disabled it.

Its value has to be a command prefix, see above, -command for a more
detailed explanation. When the callback is invoked a single additional
arguments is appended to the prefix. This argument is the number of bytes
which were transfered so far.

-size int
This option specifies the number of bytes to read from the input data and
transfer. It is optional and defaults to "Transfer everything". Its value
has to be an integer number and any value less than zero has the same
meaning, i.e. to transfer all available data. Any other value is the amount
of bytes to transfer.

All transfer commands will throw error an when their user tries to transfer
more data than is available in the input. This happens immediately, before
the transfer is actually started, should the input be a string. Otherwise
the, i.e. for a channel as input, the error is thrown the moment the
underflow condition is actually detected.

-encoding encodingname

-eofchar eofspec

-translation transspec
These options are the same as are recognized by the builtin command
fconfigure and provide the settings for the output channel which are to be
active during the transfer, and only then. I.e. the settings of the output
channel before the transfer are saved, and restored at the end of a
transfer, regardless of its success or failure. None of these options are
required, and they default to the settings of the output channel if not
specified.

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://sourceforge.net/tracker/?group_id=12883].    Please  also  report  any  ideas  for
       enhancements you may have for either package and/or documentation.

KEYWORDS

       channel, copy, transfer

COPYRIGHT

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