By default, SWI-Prolog is installed as‘swipl’. The
command line arguments of SWI-Prolog itself and its utility programs are
documented using standard Unix man pages. SWI-Prolog is normally
operated as an interactive application simply by starting the program:
$ swipl
Welcome to SWI-Prolog ...
...
1 ?-
After starting Prolog, one normally loads a program into it using
consult/1,
which may be abbreviated by putting the name of the program file between
square brackets. The following goal loads the file
likes.pl
containing clauses for the predicates likes/2 :
?- [likes].
true.
?-
Alternatively, the source file may be given as command line
arguments:
$ swipl likes.pl
Welcome to SWI-Prolog ...
...
1 ?-
Both the above assume likes.pl is in your working
directory. If you use the command line version swipl the
working directory is the same as the shell from which you started
SWI-Prolog. If you started the GUI version (swipl-win) this
depends largely on the OS. You can use pwd/0
and cd/0 to find and
change the working directory. The utility ls/0
lists the contents of the working directory.
?- pwd.
% /home/janw/src/swipl-devel/linux/
true.
?- cd('~/tmp').
true.
?- pwd.
% /home/janw/tmp/
true.
The file likes.pl is also installed in a subdirectory demo
insides SWI-Prolog's installation directory and may be loaded regardless
of the working directory using the command below. See
absolute_file_name/3
and file_search_path/2
for details on how SWI-Prolog specifies file locations.
?- [swi(demo/likes)].
true.
After this point, Unix and Windows users unite, so if you are using
Unix please continue at section
2.1.2.
After SWI-Prolog has been installed on a Windows system, the
following important new things are available to the user:
- A folder (called directory in the remainder of this
document) called
swipl containing the executables,
libraries, etc., of the system. No files are installed outside this
directory.
- A program swipl-win.exe, providing a window for interaction
with Prolog. The program swipl.exe is a version of SWI-Prolog
that runs in a console window.
- The file extension
.pl is associated with the program
swipl-win.exe. Opening a .pl file will cause
swipl-win.exe to start, change directory to the directory in
which the file to open resides, and load this file.
The normal way to start the likes.pl file mentioned in
section 2.1.1.1 is
by simply double-clicking this file in the Windows explorer.
