Configuration Variables

In addition to server variables and environment variables, some special variables are supported. These variables may not be implemented on all platforms.

`HOSTSERVER`	Returns `IIS` or `Apache`. Note that under IIS, the `SERVER_SOFTWARE` server variable can be used to retrieve the version number. However, this server variable may be undefined under Apache.
`MAXTHREADS`	Resolves to the number of threads configured in the BIS thread pool. This is the number of threads that are available for requests. Under Apache, this is undefined (use `DEFAULT=1` if portability is desired).
`REQUEST_URL`	Retrieves the completely qualified URL of the stencil (.srf) file that was requested by the client. This includes the scheme, hostname, port number (if non-standard), path, and parameters, query string, and fragment (if specified).
`REQUEST_BASE_URL`	Retrieves the completely qualified base URL of the current stencil (.srf) file that was requested by the client. This includes the scheme, hostname, port number (if non-standard), and the path (which always ends in a slash). The base URL is defined as the directory that contains the stencil that was requested by the client.
`STARTSERVICE`	Returns the entire argument list of the currently active `StartService` tag, including commas. If there is no active service program, the value is considered undefined and may be overridden with the `DEFAULT` operation.
`SCHEME`	Returns the scheme that was used to request the current page: currently returns either `http` or `https`. Note that the :// delimiter that follows the scheme is not included. This is useful for constructing URLs: <a href="{{ Value(SCHEME, CONFIG) }}:// {{ Value(HTTP_HOST,URLENCODE) }} {{ Value(HTTP_URL,GETDIR,URLDECODE,URLENCODE) }}/default.srf"> (Note that the above must be on a single line, or spaces will be inserted.) Under BIS/IIS, the scheme is derived from the `SERVER_PORT_SECURE` server variable, where a value of 0 indicates http and nonzero indicates https.
`SERVICENAME`	Retrieves the name of the currently active service program. If there is no active service program, the value is considered undefined and may be overridden with the `DEFAULT` operation.
`VERSION`	Retrieves BIS version information. The format of the version number is `aa.bb.cc.yyyy/mm/dd`, where `aa.bb.cc` indicates the numeric major/minor/patch level version, and `yyyy/mm/dd` is the build date.