Help Desk | FAQ's about Server Side Includes

FAQ's about Server Side Includes

A. Server Side Includes (SSI) are commands that are embedded within HTML comments (  ) that the web server looks for, and replaces with information on the fly. If you read the rest of this document, you will see several server side includes in action.

Q. What special needs to be done ?

A. All the files containing server side includes scripts needs to end with the ".shtml" extension. If you would like to execute server side includes from a file not ending with the ".shtml" extension, please refer the the below question "How do I make files that don't end in *.shtml server parseable?"

Q. Do server side includes have any bad sides ?

A. Web pages with server side includes, and files that are specified by the web server to be server parsed, will take longer to load than a non-server parsed web page. This is because the web server actually has to read each line of the web page when it is looking for the server side include commands.

Q. How do I make files that don't end in *.shtml server parseable ?

A. In order for the server to think your *.html files are server parseable, you will need to add the following line to your existing .htaccess file (or make a new .htaccess file):

AddType text/x-server-parsed-html .html

this will make *all* *.html files server-parsed. (if your files are *.htm put .htm instead).

By adding this line, our server will make all files that end in .shtml server parsed.

Q. I'm using PERL, how can I get access to the server side include information ?

A. PERL has a variable named $ENV that contains the environment of the script. To get access to any of the server side variables, just reference them with $ENV{'variable-name'}. For example, to get the DATE_LOCAL, use: $ENV{'DATE_LOCAL'}.

Q. How do I use server side includes in my web pages ?

A. Server side includes are powerful ways to add functionality to your web pages. Our web server supports many of the standard NCSA web server server side includes. Below is a list of all server side includes supported.

Server side includes have the following format, and are to be placed inside your *.shtml or other SERVER-PARSED web pages.

<!--#COMMAND LABEL=["]ARGUMENT(S)["]-->

The easiest way to make a server side include work, is to rename your *.html file to *.shtml.

Our server is pre-configured to have *.shtml files be server-parsed (i.e., the server will read each *.shtml file and look for server side include commands). If you don't want to rename your files *.shtml, you can edit your .htaccess file and make *.html be server parsed.

Some commands require quotes, others do not. Exact syntax is shown in the examples below.

Command Label Argument(s) Example Description exec cgi cgi to run relative to current directory  This will run the cgi specified in the argument cmd Shell command to execute  This executes the specified commands using the Bourne Shell (/bin/sh). This command is NOT expected to generate any MIME headers. config timefmt strftime formatting string  Will change the current configuration of the time variables (way that the time and date are displayed) sizefmt b, K, M (file size options)  This determines how the fsize command displays file sizes include file filename relative to current directory  This will insert the contents of the file specified into the current page. The contents of the included file are not parsed. fsize file filename relative to current directory  This inserts the size of the specified file. This is controlled by the config sizefmt command. flastmod file filename relative to current directory  This inserts the last modification time/date of the specified file. This command is controlled by the config timefmt command and the strftime formatting string echo var Enviroment variable from the following:  Used to show the contents of a server variable. Below are the variables that our server will display. Note, some are browser dependant. Argument Result AUTH_TYPE If the server supports user authentication, and the script is protects, this is the protocol-specific authentication method used to validate the user. If viewing a password protected web page, this will be the "authentication type". CONTENT_LENGTH The length of the said content as given by the client. CONTENT_TYPE For queries which have attached information, such as HTTP POST and PUT, this is the content type of the data. DATE_GMT Same as DATE_LOCAL but in Greenwich mean time (GMT). DATE_LOCAL The current date, local time zone. Subject to the timefmt parameter to the config command. DOCUMENT_NAME This file's name. DOCUMENT_ROOT The location on disk of the server's primary web site. DOCUMENT_URI This document's URI. (path and filename) GATEWAY_INTERFACE The revision of the CGI specification to which this server complies. General Format: CGI/revision. HTTP_USER_AGENT The "user agent" or web browser that the visitor is using. General Format: software/version, library/version HTTP_REFERER * only works if you came here by following a link from another page. This shows the referring document. If a visitor came to this page by following a link, the URL they came from will be shown here. HTTP_ACCEPT The MIME types which the client will accept, as given by HTTP headers. Other protocols may need to get this information from elsewhere. Each item in this list should be separated by commas as per the HTTP spec. General Format: type/subtype, type/subtype HTTP_ACCEPT_LANGUAGE The language that the visitor's web browser will accept. HTTP_CONNECTION Comments coming soon. HTTP_HOST Similar to SERVER_NAME. HTTP_UA_COLOR *Microsoft IE Tag The type of display that the visitor is using, normally "color" followed by a decimal number representing how many bits, 8 being 256 colors. HTTP_UA_CPU *Microsoft IE Tag The CPU type of the visitor's computer. HTTP_UA_OS *Microsoft IE Tag The operating system in use by the visitor. HTTP_UA_PIXELS *Microsoft IE Tag The dimensions of the visitor's web browser display in pixels. Standard VGA is 640x480. LAST_MODIFIED The last modification date of the current document. Subject to timefmt like the others. PATH The paths available to the "nobody" user of the web server. PATH_INFO The extra path information, as given by the client. In other words, scripts can be accessed by their virtual pathname, followed by extra information at the end of this path. The extra information is sent as PATH_INFO. This information should be decoded by the server if it comes from a URL before it is passed to the CGI script. PATH_TRANSLATED The server provides a translated version of PATH_INFO, which takes the path and does any virtual-to-physical mapping to it. QUERY_STRING The information which follows the ? in the URL which referenced this script. This is the query information. It should not be decoded in any fashion. This variable should always be set when there is query information, regardless of command line decoding. QUERY_STRING_UNESCAPED The unescaped version of any search query the client sent, with all shell-special characters escaped with \. REMOTE_ADDR The IP address of the remote host making the request. REMOTE_HOST The translated name of the hostname making the request. If the server does not have this information, it should set REMOTE_ADDR and leave this unset. REMOTE_IDENT If the HTTP server supports RFC 931 identification, then this variable will be set to the remote user name retrieved from the server. Usage of this variable should be limited to logging only. REMOTE_USER If the server supports user authentication, and the script is protected, this is the username they have authenticated as. If viewing a password protected web page, this will be the "username". REQUEST_METHOD The method by which the visitor's web browser is retrieving the web pages. For HTTP, this is "GET", "HEAD", "POST", etc. SERVER_ADMIN The administrator's email address configured in the server configuration file for this virtual domain name. SERVER_NAME The server's hostname, DNS alias, or IP address as it would appear in self-referencing URLs. SERVER_PORT The port this web server is running on. 80 is the standard http/web port. SERVER_PROTOCOL The name and revision of the information protcol this request came in with. General Format: protocol/revision. SERVER_SOFTWARE The name and version of the information server software answering the request (and running the gateway). General Format: name/version. SCRIPT_FILENAME UNIX path name to the script being executed. SCRIPT_NAME A virtual path to the script being executed, used for self-referencing URLs.

Command	Label	Argument(s)	Example	Description
exec	cgi	cgi to run relative to current directory	<!--#exec cgi="mycgi.cgi"-->	This will run the cgi specified in the argument
exec	cmd	Shell command to execute	<!--#exec cmd="whoami"-->	This executes the specified commands using the Bourne Shell (/bin/sh). This command is NOT expected to generate any MIME headers.
config	timefmt	strftime formatting string	<!--#config timefmt="%c"-->	Will change the current configuration of the time variables (way that the time and date are displayed)
config	sizefmt	b, K, M (file size options)	<!--#config sizefmt=k-->	This determines how the fsize command displays file sizes
include	file	filename relative to current directory	<!--#include file="myfile.txt"-->	This will insert the contents of the file specified into the current page. The contents of the included file are not parsed.
fsize	file	filename relative to current directory	<!--#fsize file="myfile.txt"-->	This inserts the size of the specified file. This is controlled by the config sizefmt command.
flastmod	file	filename relative to current directory	<!--#flastmod file="myfile.txt"-->	This inserts the last modification time/date of the specified file. This command is controlled by the config timefmt command and the strftime formatting string
echo	var	Enviroment variable from the following:	<!--#echo var=VARIABLE-->	Used to show the contents of a server variable. Below are the variables that our server will display. Note, some are browser dependant.
Argument			Result
AUTH_TYPE			If the server supports user authentication, and the script is protects, this is the protocol-specific authentication method used to validate the user. If viewing a password protected web page, this will be the "authentication type".
CONTENT_LENGTH			The length of the said content as given by the client.
CONTENT_TYPE			For queries which have attached information, such as HTTP POST and PUT, this is the content type of the data.
DATE_GMT			Same as DATE_LOCAL but in Greenwich mean time (GMT).
DATE_LOCAL			The current date, local time zone. Subject to the `timefmt` parameter to the `config` command.
DOCUMENT_NAME			This file's name.
DOCUMENT_ROOT			The location on disk of the server's primary web site.
DOCUMENT_URI			This document's URI. (path and filename)
GATEWAY_INTERFACE			The revision of the CGI specification to which this server complies. General Format: CGI/revision.
HTTP_USER_AGENT			The "user agent" or web browser that the visitor is using. General Format: software/version, library/version
HTTP_REFERER			* only works if you came here by following a link from another page. This shows the referring document. If a visitor came to this page by following a link, the URL they came from will be shown here.
HTTP_ACCEPT			The MIME types which the client will accept, as given by HTTP headers. Other protocols may need to get this information from elsewhere. Each item in this list should be separated by commas as per the HTTP spec. General Format: type/subtype, type/subtype
HTTP_ACCEPT_LANGUAGE			The language that the visitor's web browser will accept.
HTTP_CONNECTION			Comments coming soon.
HTTP_HOST			Similar to SERVER_NAME.
HTTP_UA_COLOR			*Microsoft IE Tag The type of display that the visitor is using, normally "color" followed by a decimal number representing how many bits, 8 being 256 colors.
HTTP_UA_CPU			*Microsoft IE Tag The CPU type of the visitor's computer.
HTTP_UA_OS			*Microsoft IE Tag The operating system in use by the visitor.
HTTP_UA_PIXELS			*Microsoft IE Tag The dimensions of the visitor's web browser display in pixels. Standard VGA is 640x480.
LAST_MODIFIED			The last modification date of the current document. Subject to `timefmt` like the others.
PATH			The paths available to the "nobody" user of the web server.
PATH_INFO			The extra path information, as given by the client. In other words, scripts can be accessed by their virtual pathname, followed by extra information at the end of this path. The extra information is sent as PATH_INFO. This information should be decoded by the server if it comes from a URL before it is passed to the CGI script.
PATH_TRANSLATED			The server provides a translated version of PATH_INFO, which takes the path and does any virtual-to-physical mapping to it.
QUERY_STRING			The information which follows the ? in the URL which referenced this script. This is the query information. It should not be decoded in any fashion. This variable should always be set when there is query information, regardless of command line decoding.
QUERY_STRING_UNESCAPED			The unescaped version of any search query the client sent, with all shell-special characters escaped with \.
REMOTE_ADDR			The IP address of the remote host making the request.
REMOTE_HOST			The translated name of the hostname making the request. If the server does not have this information, it should set REMOTE_ADDR and leave this unset.
REMOTE_IDENT			If the HTTP server supports RFC 931 identification, then this variable will be set to the remote user name retrieved from the server. Usage of this variable should be limited to logging only.
REMOTE_USER			If the server supports user authentication, and the script is protected, this is the username they have authenticated as. If viewing a password protected web page, this will be the "username".
REQUEST_METHOD			The method by which the visitor's web browser is retrieving the web pages. For HTTP, this is "GET", "HEAD", "POST", etc.
SERVER_ADMIN			The administrator's email address configured in the server configuration file for this virtual domain name.
SERVER_NAME			The server's hostname, DNS alias, or IP address as it would appear in self-referencing URLs.
SERVER_PORT			The port this web server is running on. 80 is the standard http/web port.
SERVER_PROTOCOL			The name and revision of the information protcol this request came in with. General Format: protocol/revision.
SERVER_SOFTWARE			The name and version of the information server software answering the request (and running the gateway). General Format: name/version.
SCRIPT_FILENAME			UNIX path name to the script being executed.
SCRIPT_NAME			A virtual path to the script being executed, used for self-referencing URLs.

FAQ's about Server Side Includes

Q. What are server side includes ?

Q. What special needs to be done ?

Q. Do server side includes have any bad sides ?

Q. How do I make files that don't end in *.shtml server parseable ?

Q. I'm using PERL, how can I get access to the server side include information ?

Q. How do I use server side includes in my web pages ?