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tcl::transform::crc32(n) Reflected/virtual channel support tcl::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
    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







  

  
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.

  

  

  
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.

  










BUGS, IDEAS, FEEDBACK


This document, and the package it describes, will undoubtedly
    contain bugs and other problems. Please report such in the category
    virtchannel of the Tcllib Trackers
    [http://core.tcl.tk/tcllib/reportlist]. 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.






KEYWORDS


channel transformation, checksum, crc32, reflected channel, tip
    230, transformation, virtual channel






CATEGORY


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COPYRIGHT


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








  

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