mkfifo

static VALUE
rb_file_s_mkfifo(int argc, VALUE *argv)
{
    VALUE path;
    int mode = 0666;

    rb_check_arity(argc, 1, 2);
    if (argc > 1) {
        mode = NUM2INT(argv[1]);
    }
    path = argv[0];
    FilePathValue(path);
    path = rb_str_encode_ospath(path);
    if (mkfifo(RSTRING_PTR(path), mode)) {
        rb_sys_fail_path(path);
    }
    return INT2FIX(0);
}