SWI-Prolog.h is in the include directory of the distribution. The distribution is normally installed in C:\Program Files\pl on Windows and /usr/local/lib/swipl-<version> on Unix.

On Unix, by default only the library for static linking libswipl.a is installed in the lib/<arch> subdirectory of the installation. On Windows, the import library swipl.lib is in the lib subfolder and swipl.dll is in the bin subfolder.

To compile C/C++ objects you need to add the include subfolder to the include directories of your compiler or you can use the swipl-ld utility. The command below creates file.obj (Windows) or file.o (Unix), passing the proper include directory to the C-compiler. This requires the SWI-Prolog programs to be available from the PATH environment variable.

swipl-ld -c file.c

To link C/C++ objects to a shared-object (DLL) you need to links against swipl.lib on Windows. On ELF based Unix platforms (most today), you do not need an import library. Often, it is much easier to let swipl-ld do the job as in the command below, which creates file.dll or file.so depending on the platform.

swipl-ld -shared -o file file.o

To embed SWI-Prolog in a C/C++ main program you need to link against the swipl library on all platforms. Again, swipl-ld simplifies the process. The first command embeds the Prolog kernel in a C main program and the second attaches a Prolog state to the result, creating a stand-alone executable.

% swipl-ld -o myexe -nostate file.o ...
% swipl-ld -o myexe file.o ... file.pl ...

Learning from swipl-ld.

If you don't want to use swipl-ld, you can learn from it by adding the -v option to the commandline, which causes the program to print the commands it runs to do its job.

See also

- Current Unix installations also provide datafiles for pkg-config. see pkg-config(1) for details.