7) Unix Services on the Hostopia Platform

• Hostopia provides users with a wide variety of UNIX services and supports such technologies as Perl, PHP, Python, MySQL and more.

• By default, UNIX services are enabled. Once a customer has enabled the Windows services, the hosting system knows to send Windows specific requests to Windows servers based on file extension. (.html, .shtml, etc. will be served by UNIX servers, .asp and .cfm requests will be served by Windows servers).  This is made possible by Hostopia’s redundant, distributed architecture.  Site content is housed on Network Filers – not individual web servers – this, along with removing individual web servers as a point of failure, allows content for one site to be served through multiple machines.

• In this system a user can mix UNIX and Windows content in the same site.

A) cgi (Common Gateway Interface) faq

• End users on the Hostopia platform will have full access to their cgi-bin directory if they have the equivalent of the BGBRONZE and higher packages.

• The cgi-bin currently supports Perl as well as PHP scripts.

• CGI - Tutorial (http://www.evolt.org/article/A_Cheesy_htaccess_Tutorial/18/226)

1. How do I upload my CGI scripts using FTP? All CGI programs must be uploaded to your cgi-bin directory. You should be sure to use ASCII mode when uploading Perl scripts.

2. How do I call my CGI script? In your HTML documents, reference your cgi script with the following path: http://www.yourdomain.tld/cgi-bin/script

3. What path do I use to call sendmail? /usr/sbin/sendmail

4. What path do I use to access files in my home directory using my cgi script? services/webpages/[first_letter_of_domain]/[second_letter_of_domain]/[domain]/[file] [domain] is replaced with your domain [file] is replaced with the filename including sub-directory information being accessed

I.E. /services/webpages/h/o/hosting.Bluegenesis.Com/chat/chat.Log

The following limitations will be placed on ALL CGI scripts:

• CPU TIME = 10 Seconds - This is the amount of CPU time one CGI program can use at a given time.

• MAXIMUM FILESIZE = 100 KBytes - This is the maximum size that one CGI script can reach

• MAXIMUM STACK SIZE = 8 MBytes - This is the amount of stack memory that can be used by any CGI program.

• MAXIMUM NUMBER OF PROCESSES = 32 Processes - This is the number of processes that can be created by the CGI program at a given time.

• MAXIMUM NUMBER OF OPEN FILES = 32 Open Files - This is the number of files that can be opened by the CGI program at a given time.

• MAXIMUM NUMBER OF OPEN CONNECTIONS TO MYSQL = 20

B) Server Side Includes (ssi) faq

• Ensure that the page with the SSI has a .shtml extension. The web server will only parse files with this extension.

• SSI are directives which you can place into your HTML (or other) documents to execute scripts or output, for example, environment variables or file statistics. SSI is an Apache feature implemented by mod_include. This feature allows us to place special code 'elements' in our documents which will carry out certain actions as specified. When a page is sent from the server to the requesting client the page is scanned by the server for the SSI code elements and carries out the required actions based on the code

• Primary uses are to provide interactivity to a web site and to aid site maintenance! For example, content which is common to all your web pages can be placed in a single document and then included on ALL your pages. To make any changes you only need to modify this source document. This is ideal for site navigation or copyright notices which are usually on all pages. Having this content in a single file means changes can be done very quickly without having to modify 10, 20 or 50 separate documents.

• Displaying document information such as document name, URI, last modified date, file size. Using the "echo command" you can 'echo' environmental variables, user information such as IP address or browser information. You can redirect visitors to a page depending on what browser version they are using. You can check what country they are from and display a custom message in their language! You can query and update a database or send an email, all without the use of a CGI script. There are almost endless uses for SSI. (c) ssi-developer.net element.

• Files with the extension .shtml (or others as explained later) are processed by the server for SSI. Config Directives

• The config command allows you to customize SSI error message which will be sent to the client if an SSI processing error occurs.

• Using the following directive will display "Sorry, the error has occurred" instead of default "[an error occurred while processing this directive]" in case if some directive on the page is not working properly: <!--#config errmsg="Sorry, the error has occurred" -->

Exec Directives

• The exec command simply executes a script or a program on the server.

• For example the following directive will run a simple helloworld.pl script located in the /cgi-bin/ directory: <!--#exec cgi="/cgi-bin/helloworld.pl" --> "Hello world" phrase will be displayed on the .shtml page containing the directive.