CGI Scripting with Perl Accelerated Technical Training for Webmasters and Site Programmers
Courseware	This is a web-based class. The training materials are at http://www.keller.com/perlweb.
Format	1 full day Emphasis on practical skills. Hands-on.
Audience	This course is for Perl programmers who wish to construct interactive web sites.
Prerequisites	Check the boxes for the prerequisites you satisfy. Perl -- You know how to write Perl scripts (we recommend our Perl Jumpstart course.) Unix or NT -- You can navigate the filesystem and edit text. HTML -- You have written web pages (we recommend our intro and part II courses.) If you checked all three boxes, you're well-equipped to get the most from this course!
Overview	Common Gateway Interface (CGI) is the technical term for the the mechanism by means of which programs are invoked on web servers in response to mouse clicks on hyperlinks by users of browsers. CGI programs perform such tasks as database updates, product ordering, survey form completion, and so on. They also generate new web pages -- termed dynamic web pages because these pages are created on the fly by the CGI programs. From the user's perspective, such pages are indistinguishable from hand-written ("static") ones. But for the owners and builders of web sites, CGI programs open vast new possibilities. This is a technical course for people with Perl programming experience who wish to apply it to the construction of web sites. The web as a platform upon which to build and deploy applications has many advantages: It is machine-independent; your software will run identically on PCs, Macintoshes, and workstations. It is timely; data and software updates are immediately available. It is easy to deploy; there is no software to distribute, since your applications run on a server and the client software is standard. It is geographically dispersed; physical proximity is irrelevant since the web is indeed World Wide. It is easy for users to learn because browsers are intuitive and already familiar to many. This course provides the techniques that enable you to gain all these benefits.
Objectives	The essential goal of the course is the acquisition of real skills. Upon completion of this course, you will be able to: Process data from HTML forms. Generate dynamic Web pages. Capture form data in files. Send e-mail from Perl scripts. Use the CGI.pm Perl module to make CGI scripting easier. Debug Perl CGI scripts. Optional/Advanced: Use the environment variables set by the Web server. Display data in real time. Add fields to the server's HTTP response header. Lock files to prevent data corruption. Grasp the issues of interfacing to legacy systems.
Textbook	Lincoln Stein, How to Set Up and Maintain a Web Site, Addison Wesley, 1997. $40.
Method	A great deal of information is covered in a short amount of time. The format is highly compressed, with a focus on hands-on exercises -- the best way to acquire new skills, learning by doing -- that are carefully designed to rehearse the specific techniques of interest without extraneous effort. Source code files are provided to save time typing. Once you get your solution working, you know you have learned -- and proven you've learned! -- each of the essential techniques for programming web-based applications in Perl. In its method, the course's emphasis is on the practical, with the majority of the classroom time devoted to hands-on activity. You set your own pace, with the instructor acting mainly as a facilitator. Historical and theoretical material is kept to a minimum. The main classroom activity is the step-by-step construction of a web-based work order and invoicing system for a hypothetical business. Each student receives a tarfile copy of the sample programs discussed in the course.
Contents	Housekeeping review of prerequisites course objectives related topics resources for Perl and CGI programmers (lots!) Review of the Basics of Perl The Client, the Server, and the Environment The terminology and mechanisms of the web are reviewed and presented with emphasis on usefulness for CGI programming: components of the web: clients, servers, and the HTTP protocol that connects them the programming features of the Common Gateway Interface (CGI), the mechanism that enables clients to run programs on servers: environment variables request types HTTP headers authentication Lab: a greeting page with a redirect to another URL (Uniform Resource Locator) determined according to the identity of the remote user Techniques for Debugging CGI Scripts In conjunction with a web server, Perl offers a flexible programming environment and a variety of techniques are available for troubleshooting: redirecting standard error output watching log files locally simulating the remote client side using Perl's command-line switches Lab: samples and practice for each method Processing Form Data Web-based forms enable gathering of data from remote users. These data must then be processed by CGI programs that: use the CGI.pm object-oriented Perl module lock the data files to prevent multi-user update anomalies handle file uploads Lab: add a field to a form, validate the datum entered there, append it to a file Dynamic Web Pages Often, the page displayed by your web browser was not written by a human but generated by a program. Its contents can vary according to circumstance, hence the termdynamic. Dynamic web page generation techniques discussed in this chapter include: maintaining state information CGI.pm HTML shortcuts Lab: write a Perl script to dynamically generate the form from the previous chapter so that it is one Perl script instead of a Perl script and an HTML form Non-Parsed Headers Non-Parsed Headers (NPH) are a useful CGI technique for: processing data in real time Lab: a progress indicator in a frame Interfacing to External Applications Building web-based interfaces to legacy applications and making use of other computer-based resources is one of the web's popular uses. The applicable techniques taught here are: file locking sending mail with attachments accessing databases Lab: retrieve service records, e-mail reminder letters Conclusion review summary tarfile of course source code
Classroom Setup	Delivery of this course requires a classroom equipped with: an overhead projector a PC or workstation for each student a PC or workstation for the instructor a projector for the instructor's computer screen connection to the internet a Perl interpreter and a webserver enabled for CGI (details) -- can run on NT or Unix
Site	The course can be taught in your classroom, anywhere in the world. Travel outside the San Francisco Bay Area requires reimbursement of the instructor's travel expense.

CGI Scripting with Perl

Accelerated Technical Training for Webmasters and Site Programmers

Courseware

This is a web-based class. The training materials are at http://www.keller.com/perlweb.

Format

1 full day
Emphasis on practical skills.
Hands-on.

Audience

This course is for Perl programmers who wish to construct interactive web sites.

Prerequisites

Check the boxes for the prerequisites you satisfy. If you checked all three boxes, you're well-equipped to get the most from this course!

Overview

Common Gateway Interface (CGI) is the technical term for the the mechanism by means of which programs are invoked on web servers in response to mouse clicks on hyperlinks by users of browsers. CGI programs perform such tasks as database updates, product ordering, survey form completion, and so on. They also generate new web pages -- termed dynamic web pages because these pages are created on the fly by the CGI programs. From the user's perspective, such pages are indistinguishable from hand-written ("static") ones. But for the owners and builders of web sites, CGI programs open vast new possibilities.

This is a technical course for people with Perl programming experience who wish to apply it to the construction of web sites.

The web as a platform upon which to build and deploy applications has many advantages:

It is machine-independent; your software will run identically on PCs, Macintoshes, and workstations.
It is timely; data and software updates are immediately available.
It is easy to deploy; there is no software to distribute, since your applications run on a server and the client software is standard.
It is geographically dispersed; physical proximity is irrelevant since the web is indeed World Wide.
It is easy for users to learn because browsers are intuitive and already familiar to many.

This course provides the techniques that enable you to gain all these benefits.

Objectives

The essential goal of the course is the acquisition of real skills. Upon completion of this course, you will be able to:

Process data from HTML forms.

Generate dynamic Web pages.

Capture form data in files.

Send e-mail from Perl scripts.

Use the CGI.pm Perl module to make CGI scripting easier.

Debug Perl CGI scripts.

Optional/Advanced:

Use the environment variables set by the Web server.
Display data in real time.
Add fields to the server's HTTP response header.
Lock files to prevent data corruption.
Grasp the issues of interfacing to legacy systems.

Textbook

Lincoln Stein, How to Set Up and Maintain a Web Site, Addison Wesley, 1997. $40.

Method

A great deal of information is covered in a short amount of time. The format is highly compressed, with a focus on hands-on exercises -- the best way to acquire new skills, learning by doing -- that are carefully designed to rehearse the specific techniques of interest without extraneous effort. Source code files are provided to save time typing. Once you get your solution working, you know you have learned -- and proven you've learned! -- each of the essential techniques for programming web-based applications in Perl.

In its method, the course's emphasis is on the practical, with the majority of the classroom time devoted to hands-on activity. You set your own pace, with the instructor acting mainly as a facilitator. Historical and theoretical material is kept to a minimum. The main classroom activity is the step-by-step construction of a web-based work order and invoicing system for a hypothetical business.

Each student receives a tarfile copy of the sample programs discussed in the course.

Housekeeping
- review of prerequisites
- course objectives
- related topics
- resources for Perl and CGI programmers (lots!)
Review of the Basics of Perl
The Client, the Server, and the Environment
The terminology and mechanisms of the web are reviewed and presented with emphasis on usefulness for CGI programming:
- components of the web: clients, servers, and the HTTP protocol that connects them
- the programming features of the Common Gateway Interface (CGI), the mechanism that enables clients to run programs on servers:
  - environment variables
  - request types
  - HTTP headers
  - authentication
- Lab: a greeting page with a redirect to another URL (Uniform Resource Locator) determined according to the identity of the remote user
Techniques for Debugging CGI Scripts
In conjunction with a web server, Perl offers a flexible programming environment and a variety of techniques are available for troubleshooting:
- redirecting standard error output
- watching log files
- locally simulating the remote client side
- using Perl's command-line switches
- Lab: samples and practice for each method
Processing Form Data
Web-based forms enable gathering of data from remote users. These data must then be processed by CGI programs that:
- use the CGI.pm object-oriented Perl module
- lock the data files to prevent multi-user update anomalies
- handle file uploads
- Lab: add a field to a form, validate the datum entered there, append it to a file
Dynamic Web Pages
Often, the page displayed by your web browser was not written by a human but generated by a program. Its contents can vary according to circumstance, hence the termdynamic. Dynamic web page generation techniques discussed in this chapter include:
- maintaining state information
- CGI.pm HTML shortcuts
- Lab: write a Perl script to dynamically generate the form from the previous chapter so that it is one Perl script instead of a Perl script and an HTML form
Non-Parsed Headers
Non-Parsed Headers (NPH) are a useful CGI technique for:
- processing data in real time
- Lab: a progress indicator in a frame
Interfacing to External Applications
Building web-based interfaces to legacy applications and making use of other computer-based resources is one of the web's popular uses. The applicable techniques taught here are:
- file locking
- sending mail with attachments
- accessing databases
- Lab: retrieve service records, e-mail reminder letters
Conclusion
- review
- summary
- tarfile of course source code

Classroom Setup

Delivery of this course requires a classroom equipped with:

an overhead projector
a PC or workstation for each student
a PC or workstation for the instructor
a projector for the instructor's computer screen
connection to the internet
a Perl interpreter and a webserver enabled for CGI (details) -- can run on NT or Unix

Site

The course can be taught in your classroom, anywhere in the world. Travel outside the San Francisco Bay Area requires reimbursement of the instructor's travel expense.

Dan Keller Technical Services
2248 International Blvd., Oakland
California, USA 94606
tel: 415 / 861-4500