9.4.15 Errors and warnings

PL_warning() prints a standard Prolog warning message to the standard error (user_error) stream. Please note that new code should consider using PL_raise_exception() to raise a Prolog exception. See also section 4.10.

int PL_warning(format, a1, ...)

Print an error message starting with `[WARNING: ', followed by the output from format, followed by a `]' and a newline. Then start the tracer. format and the arguments are the same as for printf(2). Always returns FALSE.