Initialize the interpreter file I/O intrinsics
int SLang_init_slfile (void)
This function initializes the interpreters file I/O intrinsic
functions. This function adds intrinsic functions such as
fopen, fclose, and fputs to the interpreter.
It returns 0 if successful, or -1 upon error.
Before this function can be called, it is first necessary to call
SLang_init_slang. It also adds
the preprocessor symbol __SLFILE__ to the interpreter.
SLang_init_slang, SLang_init_slunix, SLang_init_slmath