# Site and personal initialisation files

On startup, SWI-Prolog reads both site initialisation and personal
initialisation files. Both can be controlled explicitly using
commandline options (*|-F base|* for site, and *|-f base|* for personal
initialisation).

The site-initialisation file is located in the SWI-Prolog home
directory. Its name is deduced from the commandname by taking the
leading alphanumerical characters, followed by the extension =|.rc|=.
Using default installation this implies *|swipl.rc|* for the Unix version
and *|swipl-win.rc|* for the Windows GUI version.

If XPCE is installed, it is activated through the above named system
default file.

The personal initialisation file depends on version and OS:

  - 8.1 and later <br>
    The file is called `init.pl` and resides in a directory
    `swi-prolog` below the the [XDG](https://wiki.archlinux.org/index.php/XDG_Base_Directory) config home.  On Unix the
    default XDG config home is ``~/.config``.  On Windows it
    is the directory provided by win_folder/2 on `local_appdata`.

    These files are available using the file_search_path/2 alias
    `user_app_config` as well as the deprecated aliases
    `user_profile` and `app_preferences`

  - Up to 8.0 <br>
    The file is named ``.swiplrc`` on Unix (``.plrc`` for really old
    versions) and ``swipl.ini`` on Windows (``pl.ini`` for really old
    versions).  The file resides in the user's home (Unix) or in the
    ``appdata`` directory (Windows).

    These files are available using the file_search_path/2 alias
    `user_profile`.

In *|plwin.exe|*, the personal initialisation file is accessible through
the *|Settings menu|*. On first use, it copies a default file with some
commented commonly used customization options. The same behaviour is
also available from the PceEmacs menu _|Edit/Prolog preferences|_.

The *|-s file|* command line option is often used on Unix systems to
load and start applications using a single command. This option can also
be used to create PrologScript.txt files. Recent versions interpret a
``*.pl`` file on the command line as a source file. When used in a
terminal, a session is typically started as

    swipl file.pl