This Guide is aimed at people who wish to write their own WWW executable scripts using WWW's Common Gateway Interface ( CGI). Though the main emphasis is on REXX many examples are also provided in Perl.
There are some simple software libraries to facilitate writing CGI scripts. cgi-lib.rxx is a REXX library of functions (available at SLAC by using the REXX CALL PUTENV 'REXXPATH=/afs/slac/www/slac/www/tool/cgi-rexx'statement to include the library at execution time)and cgi-lib.pl is a similar library in Perl written by Steve Brenner (there is an executable copy of this libary at SLAC in /afs/slac/g/www/cgi-lib/cgi-lib.pl). NCSA has a very useful set of Perl CGI handler subroutines that are available via anonymous FTP.Another set of Perl CGI Server Side Scripts written by Brigitte Jellinek is available under Gnu public license. There is also the Source code for www.stanford.edu scripts and programs. There is also an index to Perl WWW programs gathered by Earl Hood. Finally see the Web Development Center.
Since there are security and other risks associated with executing user scripts in a WWW server, the reader may wish to first view a document providing information on a SLAC Security Wrapper for users' CGI scripts. Besides improving security, this wrapper also simplifies the task of writing a CGI script for a beginner.
Before embarking on writing a script, you may also want to check out some rough notes on SLAC Web Utilities Provided by CGI Scripts.
The CGI is an interface for running external programs, or gateways, under an information server. Currently, the supported information servers are HTTP (the Transport Protocol used by WWW) servers.
Gateway programs are executable programs (e.g. UNIX scripts) which can be run by themselves (but you wouldn't want to except for debugging purposes). They have been made executable to allow them to run under various (possibly very different) information servers interchangeably. Gateway programs conforming to this specification can be written in any language, including REXX or Perl, which produces an executable file