trf-intro - Introduction to Trf
package require Tcl ?8.2?
package require Trf ?2.1.3?
The package Trf provides a number of commands which take data and transform them in various ways.
The implementation of Trf began as proof-of-concept of the validity and usefulness of the "stacked channel" patches to the core. These patches allow the writing of extensions to the generic I/O system of the core which are able to intercept all read/write operations on designated channels, thus giving it the ability to transform the data flowing through these channels as desired.
This allows things like transparent encryption, compression, charset recoding, etc.
Since version 8.2 of the tcl core the aforementioned patches are part of the tcl core itself, changing the status of trf from "extension requiring core patches" to "normal extension".
Other packages built upon either the stackd channels directly, or Trf are:
- TrfCrypt, by myself, contains various encryption systems
- TLS, an SSL/TLS implementation by Matt Newman.
- Tcl MIME by Marshall Rose.
The commands provide by trf can be placed into the three categories listed below. Note that all commands are added to the global namespace.
- The encoding commands either take some data and return the same data in encoded form, or take encoded data and return a decoded result.
- Message Digests
- The second category are message digests in general, simple ones like crc, and cryptographically strong algorithms like md5.
- At last a number of commands not readily placed into categories providing password crypting, general transformations, data compression, error correction and others.
adler, ascii85, base64, bz2, crc, crc-zlib, crypt, haval, hex, md2, md5, md5_otp, md5crypt, oct, otp_words, quoted-printable, ripemd-128, ripemd-160, rs_ecc, sha, sha1, sha1_otp, transform, uuencode, zip
compression, encoding, error correction, message digest, transformation
Copyright (c) 1996-2003, Andreas Kupries <firstname.lastname@example.org>
|2.1.3||Trf transformer commands|