Tcl/Tk Workshop `95 - Saturday: Session 10

Two Years with TkMan: Lessons and Innovations

Thomas A. Phelps

Theme of talk is using what you have effectively! Thomas first discussed features of TkMan. Tcl/Tk runs without extensions. Version 1.6 has had 1,500 downloads from Berkeley since December 1994. Large script ~4,000 lines with ~500 modules.

Speed up issues:

  1. Heavy character by character processing
  2. Caching pre-processed disk file
  3. To find man page, faster to exec gzcat + sed + grep on disk than searching large Tcl List {editor note: even faster to use info exists array(page)}
  4. Searching within man page needed to wait for text widget in Tk 4.0
  5. Help page (in HTML), pre-processed
  6. Removed comments and whitespace in production copy

Questions:

Prototyping NBC's GEnesis Broadcast Automation System Using Tcl/Tk

Brion D. Sarachan, Alexandra J. Schmidt, and Steven A. Zahner

Goal is to have unified control system for various aspects of broadcast system. Old system divided responsibility by equipment, new system divides responsibility by video channel. Tcl/Tk chose for ability to do rapid prototyping and modifications as well as power and flexibility of Tk widgets.

Major revisions to User Interface delivered every two (2) weeks. Data is stored in Sybase database. Extensions added to handle time. Users sybtcl, Tcl-DP and GE extensions.

Questions:

Customization and Flexibility in the exmh Mail User Interface

Brent Welch

Currently has over 24,000 lines of Tcl in over 70 files, many contributed by others. Built as modules with table driven preferences and installation. Uses no extensions, namespaces may be used in the future.

User Liberia to override and extend. This caused problems with TclX and Tcl-Dp. A class system would make overrides much easier.

Installation script supports generic installs and is table driven. Tables used in install and preferences can both be edited from Tk table editor. Widget attributes can be modified in the X11 resource database. Each toplevel has its own class. X11 resources have three levels:

  1. app-defaults (factory settings)
  2. local-default (site settings)
  3. .exmh-defaults (user settings)

Buttons and menus can also be added from X11 resources. Both user and site buttons/menus can be defined. Application (or site) buttons/menus can also be removed.

Several hooks are also provided.

Questions:

Experience with Tcl/Tk for Scientific and Engineering Visualization

Brian W. Kernighan

Problem regards design of wireless communication system. Several parts of problem (for example: RF calculations) done by others. Done in pure Tcl/Tk hooking to C programs with pipes. Small amounts of data transferred via pipes, large amounts done via files. Large use of extensive use of canvas and tags. Takes a long time to copy a canvas.

Production version needed to be run on Windows and Windows/NT. Re-implemented in Visual Basic.

Questions:

Tcl Extensions for Network Management Applications

J. Shonwlder and H. Langendorfer

A distributed network management system based on extensions to Tcl. Use agents to do management. Following extensions added:

Problems encountered with Tcl:

Questions: