The cgi.tcl Home Page

Introduction

cgi.tcl is the CGI support library for Tcl programmers. The library is very thorough - it supports forms, tables, cookies, file upload, plug-ins, JavaScript, Netscape extensions, etc, etc. It also provides very convenient support for debugging and handling CGI errors.

cgi.tcl can also be used for generating static html (such as this page). This enables you to get programming features into HTML, such as variables, if/then/else, file I/O, etc. For example, HTML lacks variables so if you repeatedly use a link on a page and one day the link changes, you've got to update every use of the link, possibly on hundreds of pages. By storing the link in a Tcl variable, you can just change the one place where the variable is defined. This makes maintenance much easier. This is just a tiny example of the benefits cgi.tcl provides.

cgi.tcl runs on any system (UNIX, Win, or Mac) which supports all versions of Tcl from 7.4 to 8.2. The current version of cgi.tcl is 1.10.0. Frequently asked questions are answered in the FAQ. A list of changes, bug fixes, enhancements is available in the History file. Noteworthy recent developments:

9/12/99 - Jeffrey Hobbs' new input routine added. 300% speed improvement if you're using Tcl 8.2 or newer.

6/25/98 - instructions for MacOS added.

4/1/98 - more new examples (framed or unframed) - vote for a t-shirt!

12/10/96 - binary upload support!

You can get cgi.tcl and the examples from expect.nist.gov as cgi.tcl.tar.Z or cgi.tcl.tar.gz. The gz file is preferrable simply because it is quicker to download. However, if you have no idea what to do with a gz file once you've got it, just transfer the Z version of the distribution.

If you are on UNIX, at the command line, type:

 uncompress cgi.tcl.tar.Z
 tar -xvf cgi.tcl.tar

If you are on Win95, Win98, or NT, download the distribution into a directory that is in the lib path of Tcl such as c:\\tcl\\lib\\tcl8.0 (note double back slashes). Unpack the distribution using WinZip95 or some equivalent program.

This will create a directory containing the cgi.tcl distribution. Change to that directory and read the README file.

If you are on MacOS, unpack the distribution and read the README file.

Note 1: cgi.tcl requires Tcl. If you don't already have Tcl, you can get it as tcl.tar.Z or ...gz. To install Tcl, just mimic the instructions as for cgi.tcl.

Note 2: If you want to download cgi.tcl (or Tcl) without using a web browser, you will need to know the ftp-style URLs. Yes, they're a lot longer and clumsier than the web-style URLs. The ftp URLs are:

	ftp://ftp.nist.gov/mel/div826/subject/expect/cgi.tcl/cgi.tcl.tar.gz (or .Z)
	ftp://ftp.nist.gov/mel/div826/subject/expect/cgi.tcl/tcl.tar.gz (or .Z)
	

Downloadable examples

You can try out the examples (framed or unframed) without downloading the distribution. On each example page, there is a link to view the source.

If you would like to show off what you've written with cgi.tcl, give me an html-formatted blurb and I'll add it to a page of real applications or puts it in the contributed scripts directory.

Documentation

• Libes, D., Writing CGI Scripts in Tcl (ps), Proceedings of the Fourth Annual Tcl/Tk Workshop '96, Monterey, CA, July 10-13, 1996. - This paper provides a high-level overview of the ideas behind cgi.tcl with many examples. I recommend you read this paper before using cgi.tcl.
• The draft reference manual contains the precise definition of the cgi.tcl library. This document can also be found in doc/ref.txt inside the cgi.tcl distribution.
• The README from the cgi.tcl distribution has lots of valuable information that has yet to be incorporated into this home page. It includes a description of the software distribution, where and how to send bug reports, how to get support, and some other background information.
• Examples can be found on the web (framed or unframed), or in the example directory of the distribution. There are examples demonstrating cookies, error handling, running /bin/passwd, file upload, visitor counting, etc.
• cgi.tcl was written around the end of '95 and then rewritten after writing the Tcl/Tk Workshop paper on it in early '96. Except for minor bug fixes and some new features, it's been quite stable since then. A list of changes, bug fixes, enhancements is available in the History file. It also provides an easy way of finding out if you need to upgrade.

Other closely-related work or papers

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• The Red Olive toolkit provides is a higher-level library sits on top of cgi.tcl and provides very elegant pages with even simpler code.