tcl::transform::crc32(nReflected/virtual channel suppotcl::transform::crc32(n)______________________________________________________________________________NAME
tcl::transform::crc32 - Crc32 transformation
SYNOPSIS
package require Tcl 8.6
package require tcl::transform::core ?1?
package require tcl::transform::crc32 ?1?
::tcl::transform::crc32 chan -option value...
_________________________________________________________________DESCRIPTION
The tcl::transform::crc32 package provides a command creating a channel
transformation which passes the read and written bytes through
unchanged (like tcl::transform::identity), but additionally continu‐
ously computes the crc32 checksums of the data it has seen for each
direction and stores them in Tcl variables specified at construction
time. The checksum in question is zlib's crc32.
Related transformations in this module are tcl::transform::adler32,
tcl::transform::counter, tcl::transform::identity, and tcl::trans‐
form::observe.
The internal TclOO class implementing the transform handler is a sub-
class of the tcl::transform::core framework.
API
::tcl::transform::crc32 chan -option value...
This command creates a crc32 checksumming transformation on top
of the channel chan and returns its handle. The accepted options
are
-read-variable varname
The value of the option is the name of a global or names‐
paced variable, the location where the transformation has
to store the crc32 checksum of the data read from the
channel.
If not specified, or the empty string, the checksum of
the read direction is not saved.
-write-variable varname
The value of the option is the name of a global or names‐
paced variable, the location where the transformation has
to store the crc32 checksum of the data written to the
channel.
If not specified, or the empty string, the checksum of
the write direction is not saved.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category virtchan‐
nel 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 transformation, checksum, crc32, reflected channel, tip 230,
transformation, virtual channel
CATEGORY
Channels
COPYRIGHT
Copyright (c) 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>
virtchannel_transform 1 tcl::transform::crc32(n)
