Chapter 1. Tutorial 1: The Interactive Command Line Interface

Table of Contents
1.1. Starting the athenaCL Interpreter
1.2. Introduction to Commands
1.3. Viewing Command Names
1.4. Executing Commands
1.5. Getting Help for Commands
1.6. Configuring the User Environment

This tutorial provides essential information and examples for using athenaCL's interactive command-line Interpreter. This material is essential for understanding basic athenaCL operation and how to obtain help within the program.

1.1. Starting the athenaCL Interpreter

Depending on your platform, there are a number of different ways to launch the athenaCL program and start the athenaCL Interpreter. For all platforms, using athenaCL requires installing (or finding) Python 2.3 (or better) on your system. Many advanced operating systems (UNIX-based operating systems including GNU/Linux and MacOS X) ship with Python installed. Earlier versions of Python (down to 2.2) may work on some platforms; 2.3, however, is recommended. Python is a free, open-source programming language available on every platform.

For complete instructions on installing and launching athenaCL in each platform, please see the file "README.txt" included in the athenaCL distribution and in Appendix A.

Whenever new Python ".py" source files are run, the Python interpreter creates ".pyc" or ".pyo" files for each source file. These files are compiled-byte code. The first time athenaCL is launched, many of these files are created. After this initial launch, users will notice a significant acceleration in application startup time. After launching athenaCL, the user is presented with a text-based display in a terminal window. The user is presented with the following initialization information:

Example 1-1. Initialization information

athenaCL 1.4.8 (on darwin via terminal threading off)
Enter "cmd" to see all commands. For help enter "?".
Enter "c" for copyright, "w" for warranty, "r" for credits.

[PI()TI()] ::

When starting up the Interpreter, athenaCL looks in the athenaCL directory for the "libATH" folder, and then various directories within the "libATH" folder. These directories contain essential files and must be present for the program to run. The athenaCL prompt "::" is preceded by information concerning the AthenaObject. This will be explained in greater detail below.