Let’s say that you’re building a large website in HTML. The client wants to display a copyright declaration on each page of the site using the current year. If the year is hard-coded on the site on each page, this would require yearly updates of each page on the site. An easier option would be to take advantage of Server Side Includes (SSI) features. This, of course, assumes that you have set up SSI on your server as described in my previous posts.
The solution looks like this:
<html> <body> <p>This page demonstrates how to display a copyright notice using the current year on the server.</p> <!--#config timefmt="%Y" --> <p>Copyright © <!--#echo var="DATE_LOCAL"--></p> </body> </html>
This solution takes advantage of two SSI directives, config and echo, plus the system variable, DATE_LOCAL.
The echo directive allows you to display an HTTP environment variable. Availability of a particular environment variable may depend on the server you are using. DATE_LOCAL is available on both the Windows IIS server on my local machine and the Apache server on my ISP. The default format displayed by <!--#echo var="DATE_LOCAL"--> will depend on how the system is set up. On my Windows IIS server, the default looks like Wednesday April 18 2012. On my ISP running Apache, it looks like Wednesday, 18-Apr-2012 11:20:38 CDT. This, however, is not the format desired for the above scenario.
We can configure what format to use for the date by using the config SSI directive. The following timestamp format codes are available. In our example, we want just the year, so we’ll use %Y like this:
<!--#config timefmt="%Y" -->.
| Value | Description | Example |
%a |
Abbreviated weekday name | Sun |
%A |
Full weekday name | Sunday |
%b |
Abbreviated month name | Feb |
%B |
Full month name | February |
%c |
Standard date & time | Mon Oct 22 11:21:55 2004 |
%d |
Day of month as digit | 12 |
%H |
Hour number (24-hour clock) | 22 |
%I |
Hour number (12-hour clock) | 10 |
%j |
Day of the year as digit | 047 |
%m |
Month as digit | 06 |
%M |
Minute number | 02 |
%p |
AM or PM | PM |
%S |
Second number | 1071178029 |
%U |
Week number | 05 |
%w |
Day of the week number (with Sunday as first day) | 1 |
%x |
Date in standard format | 01/12/05 |
%X |
Time in standard format | 12:04:45 |
%y |
Two-digit year number | 04 |
%Y |
Four-digit year | 2004 |
%Z |
Time zone | EST |
References:
http://www.yourhtmlsource.com/sitemanagement/ssiecho.html
http://en.wikipedia.org/wiki/Server_Side_Includes
http://publib.boulder.ibm.com/iseries/v5r2/ic2924/info/rzaie/rzaieenvvar.htm
