Did you know ... | Search Documentation: |
PL_initialise() |
Special consideration is required for argv[0]
. On Unix,
this argument passes the part of the command line that is used to locate
the executable. Prolog uses this to find the file holding the running
executable. The Windows version uses this to find a module
of the running executable. If the specified module cannot be found, it
tries the module libswipl.dll
, containing the Prolog
runtime kernel. In all these cases, the resulting file is used for two
purposes:
boot.prc
file from the SWI-Prolog home directory. See also qsave_program/[1,2]
and section 12.5.PL_initialise() returns 1 if all initialisation succeeded and 0 otherwise.bugVarious fatal errors may cause PL_initialise() to call PL_halt(1), preventing it from returning at all.
In most cases, argc and argv will be passed
from the main program. It is allowed to create your own argument vector,
provided
argv[0]
is constructed according to the rules above. For
example:
int main(int argc, char **argv) { char *av[10]; int ac = 0; av[ac++] = argv[0]; av[ac++] = "-x"; av[ac++] = "mystate"; av[ac] = NULL; if ( !PL_initialise(ac, av) ) PL_halt(1); ... }
Please note that the passed argument vector may be referred from Prolog at any time and should therefore be valid as long as the Prolog engine is used.
A good setup in Windows is to add SWI-Prolog's bin
directory to your PATH
and either pass a module holding a
saved state, or
"libswipl.dll"
as argv[0]
. If the Prolog state
is attached to a DLL (see the -dll option of swipl-ld),
pass the name of this DLL.