Implementing custom CGI scripts

Implementing custom CGI scripts

Our UNIX web servers have the capability to run CGI scripts in your very own "cgi-local" directory. Scripts may be written in Perl, Unix SH, KSH, CSH, and C (NOT C++) languages. Perl is our language of choice as it is a world standard and is well suited to CGI. In addition, Perl code does not require manual compilations whereas C code must be compiled on our web servers prior to use.

NT hosting customers have a "cgi-bin" directory for PERL scripts.

Here are some helpful tips to follow when installing scripts;

UNIX Shell Scripts

Upload to your cgi-local directory to ensure proper file permission settings
Upload in ASCII transfer mode (and NOT BINARY mode)
The first line of each script must read: #!/bin/sh , #!/bin/csh or #!/bin/ksh based on whichever shell scripts you prefer using.
Reference the script using /cgi-local (and NOT /cgi-bin)
Always remember to include echo "Content-type: text/html\n\n"

Perl Scripts

Upload to your cgi-local directory to ensure proper file permission settings
Upload in ASCII transfer mode (and NOT BINARY mode)
The first line of each script must read: #!/usr/local/bin/perl
Use the Perl script checker in your Control Panel to check syntax.
Reference the script using /cgi-local (and NOT /cgi-bin)
Always remember to include print "Content-type: text/html\n\n"; or alternatively using the Perl module CGI.pm (If you do not, your scripts will not run and you will get an Internal Server Error message).

use CGI qw(:cgi-lib :standard);
print header();

If a script calls another file within your account, but the script does NOT require a URL, you need to use the system path. Instead of using the absolute path to your home directory ("/www26/web/someid"), you should instead use the DOCUMENT_ROOT environment variable ($ENV{DOCUMENT_ROOT} in Perl) to determine the path of your files or programs within a script.

e.g.

From:
/www23/web/yourid/data/fact.html

To:
$ENV{DOCUMENT_ROOT}/data/fact.html

The UNIX system path to the sendmail program on your server is
/usr/lib/sendmail

The UNIX system path to the date command is
/sbin/date

C compilations

We can run only two C compilations for you. As such, we suggest Perl as an alternative scripting language. C++ is NOT supported.

If you would like to implement code that is written in C, you will first need to create and upload a makefile to your hostings account's cgi-local directory along with the source code. Once the makefile and code has been uploaded, you will need to contact Technical Support request that we compile the code. Note: You must create the makefile; we cannot compile the code without a makefile.

The code for a simple makefile is included below. If you need further information on creating makefiles, we suggest that you review the 'make' documentation or consult a tutorial on the 'make' program. We are unable to assist in the creation or editing of the makefile.

The following is a samle makefike:

CC=cc
AR=ar

test: test.cgi
test.cgi: test.h test.c ${CC} -o test.cgi test.c

Other Resources
DOS based Perl editor
comp.lang.perl.misc
comp.infosystems.www.authoring.cgi