Interprocess Comm w/Tcl

Overview

In a world of distributed computing, getting your programs to talk to each other is vital. And Tcl greatly simplifies the process of creating network-enabled applications. A single Tcl command can connect a client to a server, and you can create useful, multi-client servers in less than 50 lines of Tcl code.

In this course you will learn

All of Tcl’s mechanisms for interprocess communication including TCP/IP sockets as well as additional features such as implementing timers ant timeouts.

Recommended coding patterns for handling buffering and blocking problems

Techniques for implementing multi-client servers

Intended Audience

This course is recommended for people with a basic Tcl programming background who need to create programs incorporating interprocess communication support.

Prerequisites

Students should have taken the Introduction to Tcl/Tk course, or have equivalent Tcl knowledge. Although Tcl can run on a number of operating systems, the course is normally taught in a UNIX/Linux or Windows environment; student need to be familiar with basic file system use (file system navigation; creating/opening files; etc.).

Training Approach

This is an intensive, interactive course, which is approximately 70% lecture and 30% lab. Questions are highly encouraged. On the final day, students are given access to a zipped file containing all of the solutions to the labs and the examples used throughout the course.

Course Outline

Day 1

Basic Interprocess Pipes

A Review of the “exec” Command

Drawbacks of “exec”

Opening Interactive Pipes to Other Programs

Write Pipes

Read Pipes

Lab 1

Event-Driven Programming

Bi-Directional Pipes

Buffering Issues

Flushing Channels

Non-Blocking Channels

Asynchronous Communication

The Tcl Event Loop

Handling Multiple Processes

Lab 2

Network Sockets

The Limitations of Pipes

TCP/IP Sockets in Tcl

Client Sockets

Lab 3

Server Sockets

Standard Server Socket Setup

Lab 4

Timers and Timeouts

Timers

Simple Sleeping

Scheduling Actions

Building Good Actions

Repeating Actions

Canceling Scheduled Actions

Lab 5

Implementing Timeouts

Lab 6