root/tags/lgt2305/INSTALL.txt

================================================================
Logtalk - Open source object-oriented logic programming language
Release 2.30.5

Copyright (c) 1998-2007 Paulo Moura.  All Rights Reserved.
================================================================


The recommended way of installing Logtalk is to use, whenever possible, one 
of the provided installers. This file contains detailed instructions for 
manual installation and configuration of Logtalk. You should also consult 
the "scripts/NOTES.txt" and "integration/NOTES.txt" files for a description 
of a set of shell scripts that might be used for Logtalk installation on 
some operating-systems and for easy Logtalk integration with popular Prolog 
compilers.

Note that the broad compatibility of Logtalk, both with Prolog compilers and 
operating-systems, together with all the possible user scenarios, means that 
installation can vary from very simple by running a couple of scripts to the 
need of patching both Logtalk and Prolog compilers to workaround the lack of 
strong Prolog standards.


1. LOGTALK BASIC INSTALLATION

Installing Logtalk can be as simple as decompressing the downloaded archive 
and copying the resulting directory to a suitable location. This location 
depends on the working environment and on the number of users. The Logtalk 
directory can reside in any user accessible location. Whenever possible, it 
is recommended that Logtalk be installed by a user with administrative rights, 
as described below. This leads to a setup where each Logtalk user may freely 
try and modify the provided examples, library, and configuration files with 
the option of, at any time, restoring the files to its original state by 
simply running one of the provided scripts.


* Installing for a single user with no administrative rights:

In the case of a single user with no administrative rights, the Logtalk 
directory may simply be copied to the user home directory.


* Installing for one or more users by a user with administrative rights:

In the case of installation by a user with administrative rights, the Logtalk 
directory can be copied to any location that its accessible by all the users 
(assuming that copying the Logtalk directory to each user home directory is, 
for some reason, not feasible or desired).

The "scripts" sub-directory contains shell scripts for easy installation of 
Logtalk on POSIX operating systems (see the "scripts/NOTES.txt" file for 
details). Starting from the Logtalk directory, type:

    % cd scripts
    % sudo ./install.sh

This installation script makes all files read-only for non-admin users in 
order to avoid user tempering. This is a convenient setup for computer labs, 
given that making directories world-writable is a security risk.


2. SETTING LOGTALK ENVIRONMENT VARIABLES

You need to set two environment variables, LOGTALKHOME and LOGTALKUSER. The 
environment variable LOGTALKHOME should be set to the Logtalk installation 
directory. The environment variable LOGTALKUSER should point to a directory 
in your home directory where you want to store the user-specific Logtalk files
(by default, ~/logtalk). Both environment variables may be set for all users 
by a user with administration privileges. The two environment variables can 
have the same value if you are the only Logtalk user on your computer and if 
you have full permissions to the Logtalk installation directory. In addition, 
you may want to add the Logtalk sub-directory "xml", which contains useful 
scripts for processing XML documenting files, to your execution path.

>> POSIX systems:

If you use a csh shell, add the following line to your ~/.cshrc file:

    setenv LOGTALKHOME /your/logtalk/installation/directory
    setenv LOGTALKUSER $HOME/logtalk
    setenv PATH $PATH:$LOGTALKHOME/xml:$LOGTALKHOME/scripts

If you use a bash shell, add the following lines to your ~/.profile file:

    LOGTALKHOME=/your/logtalk/installation/directory
    LOGTALKUSER=$HOME/logtalk
    PATH=$PATH:$LOGTALKHOME/xml:$LOGTALKHOME/scripts
    export PATH LOGTALKHOME LOGTALKUSER

When using the provided shell script for installing Logtalk, a symbolic link 
to the Logtalk installation directory is automatically created. The link is 
named "logtalk". In this case, you may use this symbolic link to define the 
LOGTALKHOME environment variable in order to avoid breaking it when upgrading 
Logtalk.

>> Windows systems:

In Windows 2000/XP, environment variables are defined using the System 
properties control panel. If you are a system administrator, the Windows
GUI installer sets the LOGTALKHOME environment variable for all users and 
also sets the LOGTALKUSER environment variable for the administrator user 
running the installer.


3. END-USER SETUP (COPYING LOGTALK USER-MODIFIABLE FILES TO USERS HOME DIRS)

If you installed Logtalk on your home directory, then skip this step if you 
have set both Logtalk environment variables (LOGTALKHOME and LOGTALKUSER) to 
point to the same directory.

Each user must make a local copy of the Logtalk user-modifiable files to its 
home directory. This setup allows each user to easily and independently 
customize Logtalk to its needs. These copies can be easily made by instructing
end-users to simply run the shell scripts "cplgtdirs.*" (which are described 
in the "scripts/NOTES.txt" file).

>> POSIX systems:

    % cplgtdirs

>> Windows:

    C:\> cplgtdirs

The local copies made by the "cplgtdirs" scripts have both read and write 
permissions for the user running the script. When used with one of the 
back-end Prolog compilers for which an integration script is provided on 
the "integration" directory, this setup as the advantage of allowing each 
end-user to independently customize default compilation options and library 
paths.

Windows (non-admin) users may also use the Logtalk GUI installer to setup 
their Logtalk user folder and the LOGTALKUSER environment variable.


4. CREATING NEW PROLOG TOP-LEVELS FOR AUTOMATIC LOADING OF LOGTALK

Most Prolog compilers allows the user to define an initialization file 
that is automatically consulted at startup. These initialization files
may contain directives for loading other files, such as the Logtalk 
configuration file and the Logtalk compiler. The "$LOGTALKHOME/integration" 
sub-directory contains several pre-made scripts (named "*lgt.*") for running 
Logtalk with selected back-end Prolog compilers. You can use these scripts 
as examples when creating initialization files for other Prolog compilers. 
Be sure to read the "configs/NOTES.txt" file notes on the Prolog compilers 
that you intend to use. You may also simply follow the steps described in 
the "QUICK_START.txt" file.


5. CUSTOMIZING LOGTALK

Please see the file "CUSTOMIZE.txt" for details on how to customize your 
Logtalk installation and working environment.