Running developer versions

Follow these steps to run a Logtalk developer version:

Checking out the latest development version

From the command-line, type the following commands:

$ cd ~
$ git clone lgt3git

A lgt3git directory will be created on your home directory containing a local copy of the current Logtalk development version. Later, to update your local copy to the latest development version just type:

$ cd ~/lgt3git
$ git pull

In alternative, use one of several available GUI front-ends to git.


POSIX installation

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


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

setenv LOGTALKHOME "${HOME}"/lgt3git
setenv LOGTALKUSER "${HOME}"/lgt3git
setenv PATH "${PATH}":"${LOGTALKHOME}"/tools/diagrams
setenv PATH "${PATH}":"${LOGTALKHOME}"/tools/lgtdoc/xml
setenv PATH "${PATH}":"${LOGTALKHOME}"/scripts
setenv PATH "${PATH}":"${LOGTALKHOME}"/integration

If your lgt3git directory is not in your home directory, adjust the paths above accordingly. Don’t use relative paths such as ../ or ./ in the definition of the environment variables. Some Prolog compilers have trouble expanding environment variables, resulting in file not found errors when attempting to use the Logtalk integration scripts.

Windows installation

Checkout the Logtalk development version into the directory C:\lgt3git. If you want to have Logtalk integration shortcuts for the supported Prolog compilers created, install Inno Setup Unicode 5.3.0 (or a later version) and open the C:\lgt3git\scripts\windows\logtalk.iss file. Rebuild the Windows GUI installer and run it to install the Logtalk development version. You can also download an installer for the latest git commit from AppVeyor. In alternative, install Windows Subsystem for Linux (WSL) or a Bash shell such as the one provided by Git for Windows and follow the steps above for the POSIX installation.


POSIX systems

You may run Logtalk by typing the name of the integration script with the .sh extension. For example, to run Logtalk using SWI-Prolog as the back-end compiler type

Windows systems

Use the shortcuts available from the Logtalk program group in the Start Menu. Note that, depending on the chosen backend Prolog compiler, the first run of some shortcuts may need to be run as administrator.


See the file for tips on how to customize Logtalk.

Switching between installed versions

If you want to run both stable and development versions of Logtalk on a POSIX system, you may instead keep the default values for the environment variables LOGTALKHOME and LOGTALKUSER and use the logtalk_version_select command to switch between installed versions. Simply perform a git clone of the Logtalk development version and install it by following the steps:

$ cd lgt3git/scripts
$ sudo ./

The shell script accepts an optional prefix and thus can also be used non-administrative users. For example:

$ cd lgt3git/scripts
$ ./ -p $HOME

Logtalk development versions are identified by the name that will be used once they become the next released version. Thus, simply use the logtalk_version_select command to switch between versions. For example:

$ logtalk_version_select -l
Available versions: lgt2440 lgt2441 lgt3000a32 lgt3000a33
$ sudo logtalk_version_select lgt3000a33
Switched to version: lgt3000a33