[Contents]

1. Introduction

ScriptBasic is a BASIC language interpreter with several features that makes it unique. First of all ScriptBasic itself is free and is supported by the GNU LGPL licence. Note that the GNU LGPL licence applies only to ScriptBasic itself, while the modules interfacing 3rd party software may apply different licenses. For example the module interface code for the module T<bdb> is under LGPL, but the library it uses, namely the Berkeley DB is NOT LGPL!

ScriptBasic runs on Windows NT, Windows95, Linux, Tru64 UNIX and probably on many other platforms. ScriptBasic the ideal tool to write small scripts that gurus write in Perl. However you need not be a guru to powerfully program in ScriptBasic.

This is not the only situation to consider ScriptBasic. ScriptBasic can be a valuable tool for experts as well as a language interpreter ready to be built into their application. Read the list of ScriptBasic features and decide how you can use it.

• IT IS BASIC. No question, this is the MOST important feature of ScriptBasic. There are a lot of people who can program BASIC and only BASIC. There are many people, who can not really program. Those who do not really know what programming is, and still: they write their five-liners in BASIC to solve their simple problems. They never write Perl, Tcl, Java or C. Therefore it is BASIC.

• SCRIPTING language. There are no data types in the language. You can store real numbers, integer numbers and strings in any variable. You can mix them and conversion is done automatically. Therefore the language is very simple and easy to use.

• PORTABLE Available in C source and can be compiled on UNIXes as well as on Windows NT.

• 4E LANGUAGE, which means easy to extend, easy to embed. ScriptBasic was developed to provide clean and clear interfaces around it, and inside it. It is easy to embed the language to an application and use it as a macro language just like TCL. It is also easy to implement new built-in function and new commands. You can develop dynamically loaded libraries that ScriptBasic may load at run time. The language source is clean, well documented and development guides are available.

• COMPILED CODE ScriptBasic creates intermediate compiled code, which is interpreted afterwards. This can protect intellectual property for the BASIC programmer and faster code loading.

  • Syntax analysis is done at first and only syntactically perfect programs start to run.

  • The compiled code is put into a continuous memory space and compiled code can be saved and loaded again to run without recompilation. This is vital for CGI scripts and is not available for most scripting programming languages.
  • Compiled code is binary, not readable. Therefore you can develop and distribute programs and getting some help to protect your intellectual property. You need not give the source code.

• MULTI THREAD aware. Although the current implementation is not multi thread, all the code was designed to be thread safe. You can embed the code into systems that run multiple interpreters in the same process. On the other hand the interpreter can run the same code in multiple threads and was designed to be capable handling call-back functions, and multithread programs in the future.

This documentation is the User's Guide for the so-called STANDARD variation of the interpreter. This code runs on the command line, accepts command line arguments and runs a single program in a single process. Other variations exist, which are based on the same code but exhibit different interfaces to the system. Some features for those variations may be different, but most language features probably remain the same. The variation Eszter SB Application Engine is shipped with the ScriptBasic package and is embedding the interpreter into a multi-thread, single process web server. Other embedded variations are available from independent developers.

This document describes how to use the interpreter and the programming language.