SYNOPSIS

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 continuously 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::transform::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 namespaced 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 namespaced 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.

KEYWORDS

CATEGORY

COPYRIGHT

Copyright (c) 2009 Andreas Kupries <[email protected]>