Script Control Language Introduction

The Script Control Language (SCL) is used to write OpenSTA Scripts. Scripts define the behaviour of virtual users, these are used in exercising a system under test using the OpenSTA toolset. More details on the use of OpenSTA can be found at OpenSTA.org.

SCL is a compiled programming language designed specifically for scripting the actions of virtual users during application testing. The language is much older than OpenSTA itself, although the version used in OpenSTA is not inteded to be compatible with any previous generation of the language. It does however have some legacy issues because of this history. The syntax of this simple language was clearly influenced by Fortran and Digital's DCL, but it shares few identical features with either.

This document is meant to provide a general overview and reference for the SCL Language used within OpenSTA. It is not intended to be a tutorial of SCL use within OpenSTA or any sort of user guide with details of when, how and where the specific language features are best used - this type of information is currently best found in the OpenSTA FAQ or by asking questions on the OpenSTA Users Mailing List.

The document is divided into the following sections:

• Document Conventions - how type and format is used to try to make this document easier to understand.
• General Rules - the basic features, restrictions, and structure that applies throughout the source code of SCL Script files.
• The ENVIRONMENT Section - the available commands and layout of the first section of every SCL Script.
• The DEFINITIONS Section - the available commands and layout of the optional second section to SCL Scripts. This section is where variables are defined.
• The CODE Section - the available commands and layout of the required last section of SCL Scripts. This section is where the language steps and actions are described.

A final section has been provided to cover some of the features of SCL that are broken or useless. You might find some workarounds and fixes to common problems here.