The SSI Variables

SREhttp/2 Manual|| SSIs|| SSIcache || Edit SSI_VARS.CFG SSI_VARS

SREhttp/2: Defining Server Side Include Variables

SREhttp/2 allows you to define several kinds of string variables that can be used in HTML documents subject to Server Side Includes. These variables are defined in the SSI_VARS.CFG configuration file(s).

Notes:

Notes:	The SSI_VARS.CFG files (like all SREhttp/2 configuration files) are text files SREhttp/2 uses a default SSI_VARS.CFG file (typically located in the SREHTTP2\CFG directory). SREhttp/2 also uses host-specific versions of SSI_VARS.CFG (typically located in subdirectories under the SREHTTP2\CFG directory) (see HOSTDATA.HTM for more details on SREhttp/2's `host-specific parameter files`). You can use the SREhttp/2 configurator to modify parameters in any of the SSI_VARS.CFG files.

The SSI_VARS.CFG files (like all SREhttp/2 configuration files) are text files
SREhttp/2 uses a default SSI_VARS.CFG file (typically located in the SREHTTP2\CFG directory).
SREhttp/2 also uses host-specific versions of SSI_VARS.CFG (typically located in subdirectories under the SREHTTP2\CFG directory) (see HOSTDATA.HTM for more details on SREhttp/2's host-specific parameter files).
You can use the SREhttp/2 configurator to modify parameters in any of the SSI_VARS.CFG files.

Basic Syntax

SSI_VARS.CFG consists of one-line entries. Each entry has the form:
name new_string
where

`name`	The `name` should be a short variable name with no embedded spaces. There are 3 reserved variable names: `HEADER, FOOTER,` and `REPLACE` All other names refer to variables used in `<!-- REPLACE xx -->` SSI keyphrases.
`new_string`	The new string to use. The interpretation of new string depends on the `name`.

name can refer to one of the following types of variables:

 SSI (server side include) keyphrases.
Automatic HEADER and FOOTER insertion
Replacement-rules
Lifespan of hit-cache entries

 SSI keyphrases.

The new_string should be a one-line string (of arbitrary length) to be used when the corresponding  SSI keyphrase is encountered (in an HTML document subject to server side includes).

Example:
    PHONEME Contact Joe for more info!
When a
   
occurs in your HTML file, it is replaced by,
    Contact Joe for more info!

newstring may contain up to nine %n (n=1,2,..,or 9) " argument placeholders.
These are used when a
    
then the following is used:
    Today's special is: Apples
If you define mulltiple lines with the same name, the values will be concatenated.
Example:
```
        MYADDRESS   My address is: <br>
        MYADDRESS   1800 M St NW. <br>
        MYADDRESS    Washington, DC. 20035 <br>
```
Note the addition of the <br> element -- HTML ignores CRLFs!
The name may contain dots (see examples below)
You can use the REPLACE selector-specific SSI-suppression option to suppress use of  keyphrases.
You can use SREH2_VALUE(label,,hostnickname) to look these values up, on a host-specific basis (use DEFAULT as hostnickname to lookup the default (non-host-specific) values).

HEADER and FOOTER

The new_string is inserted as a HEADER (or FOOTER).

HEADERs are inserted after the (first) <BODY> statement in an HTML document.
FOOTERS are inserted before the (last) </BODY> statement in an HTML document
If the document lacks a <BODY> or a </BODY>, then the HEADER (or FOOTER) will not be used.

If you define mulltiple HEADER or FOOTER entries, the values will be concatenated.
Example:

        FOOTER  Contact info: <br>
        FOOTER  <A href="mailto:hostmaster@foo.net">The HostMaster</A>

You can use the HEADER and FOOTER SSI-suppresion selector-specific-options to suppress insertion of headers and footers.

Replacement rules

REPLACE is used to define global replacement rules.

Global replacement rules are used to perform textual substituion on HTML documents subject to server side includes. Although only attempted on these SSI HTML documents, the REPLACE entries are not server side includes. Rather, they are textual replacements that occur throughout the document, regardless of the placement of HTML elements.

Basically, REPLACE can be useful as a way of changing values across a wide range of documents (they emulate style sheets), or as a shorthand for longer actions.

Each REPLACE entry should have the syntax:
REPLACE old_string==newstring
which means all occurences of old_string will be replaced by newstring.

Notes:

== is used to divide the old and new strings.
spaces are not stripped from newstring.
Spaces are stripped from the beginning of old_string
Option: To includes leading spaces at the start of old_string, start old_string with ==.
The == will be stripped and the leading spaces will be retained.
Example: replace == ABC ==, ABC,
Thus:
```
        replace $x==THIS is X
     will have different effects then:
        replace == $x== THIS is X
```
(the latter requires a space before the x, and will add a space before the THIS)
the match of old_string is case insensitive; but the newstring case will be maintained.
Not only will the original document be subject to REPLACE rules, so will all subsequent server side includes.
To specify an == in a new or old string, use URL-encoding (== is %2b%2b).
Note that you can specify = by using a single = sign.
If any selector-specific REPLACE rules are defined they will be used instead of these host-specific REPLACE rules.
You can use the REPLACE_RULES selector-specific SSI-suppression option to suppress use of  keyphrases.
Multiple lines starting with REPLACE rules define a set of replacement rules. Hence, replacement_rules can not span multiple lines.
Example:
```
   REPLACE ${==<-- $ customiz 
   REPLACE }==  -->
```
This will transform
Customization is ${set1.var1}
into
Customization is

Lifespan of Hit Cache entries

The hit cache is used by the  SSI keyphrase. In particular, it used to suppress augmentation of a counter when a resource is read repetitively by the same client. That is, if a client reloads a URI several times in a few minutes, then the Hit Cache will prevent this hit-counter from being augmented.

You can specify a lifespan in seconds, by setting the !HIT_DURATION variable (make sure to start with the !). If a request, by this client for this URI, has occurred within the last !HIT_DURATION seconds, then the hit counter will not be incremented (the current value of the hit counter will be returned).

Set this to 0 to disable this option (in which case all requests for the resource will cause the counter to increment).

Example:

   !HIT_DURATION 20

means augment HIT counter only if most recent request from this client was more then 20 seconds ago

Notes

hit-cache uses the client's IP address when checking how recently the client requested this resource. When multiple client's share a single IP address (say, when they lie behind a proxy server), use of this hit-cache will inappropriately suppress augmentation.
hit-cache tracks up to 250 URIs. To change this limit, see the num_hit_track parameter in SREH2INI.RXX.