;
	    FD_SET(fileno(fptr->f), rp);
	    if (READ_DATA_PENDING(fptr->f)) { /* check for buffered data */
		pending++;
		FD_SET(fileno(fptr->f), &pset);
	    }
	    if (max < fileno(fptr->f)) max = fileno(fptr->f);
	}
	if (pending) {		/* no blocking if there's buffered data */
	    timerec.tv_sec = timerec.tv_usec = 0;
	    tp = &timerec;
	}
    }
    else
	rp = 0;

    if (!NIL_P(write)) {
	Check_Type(write, T_ARRAY);
	wp = &wset;
	FD_ZERO(wp);
	for (i=0; i<RARRAY(write)->len; i++) {
	    GetOpenFile(rb_io_get_io(RARRAY(write)->ptr[i]), fptr);
	    FD_SET(fileno(fptr->f), wp);
	    if (max < fileno(fptr->f)) max = fileno(fptr->f);
	    if (fptr->f2) {
		FD_SET(fileno(fptr->f2), wp);
		if (max < fileno(fptr->f2)) max = fileno(fptr->f2);
	    }
	}
    }
    else
	wp = 0;

    if (!NIL_P(except)) {
	Check_Type(except, T_ARRAY);
	ep = &eset;
	FD_ZERO(ep);
	for (i=0; i<RARRAY(except)->len; i++) {
	    GetOpenFile(rb_io_get_io(RARRAY(except)->ptr[i]), fptr);
	    FD_SET(fileno(fptr->f), ep);
	    if (max < fileno(fptr->f)) max = fileno(fptr->f);
	    if (fptr->f2) {
		FD_SET(fileno(fptr->f2), ep);
		if (max < fileno(fptr->f2)) max = fileno(fptr->f2);
	    }
	}
    }
    else {
	ep = 0;
    }

    max++;

    n = rb_thread_select(max, rp, wp, ep, tp);
    if (n < 0) {
	rb_sys_fail(0);
    }
    if (!pending && n == 0) return Qnil; /* returns nil on timeout */

    res = rb_ary_new2(3);
    rb_ary_push(res, rp?rb_ary_new():rb_ary_new2(0));
    rb_ary_push(res, wp?rb_ary_new():rb_ary_new2(0));
    rb_ary_push(res, ep?rb_ary_new():rb_ary_new2(0));

    if (interrupt_flag == 0) {
	if (rp) {
	    list = RARRAY(res)->ptr[0];
	    for (i=0; i< RARRAY(read)->len; i++) {
		GetOpenFile(rb_io_get_io(RARRAY(read)->ptr[i]), fptr);
		if (FD_ISSET(fileno(fptr->f), rp)
		    || FD_ISSET(fileno(fptr->f), &pset)) {
		    rb_ary_push(list, RARRAY(read)->ptr[i]);
		}
	    }
	}

	if (wp) {
	    list = RARRAY(res)->ptr[1];
	    for (i=0; i< RARRAY(write)->len; i++) {
		GetOpenFile(rb_io_get_io(RARRAY(write)->ptr[i]), fptr);
		if (FD_ISSET(fileno(fptr->f), wp)) {
		    rb_ary_push(list, RARRAY(write)->ptr[i]);
		}
		else if (fptr->f2 && FD_ISSET(fileno(fptr->f2), wp)) {
		    rb_ary_push(list, RARRAY(write)->ptr[i]);
		}
	    }
	}

	if (ep) {
	    list = RARRAY(res)->ptr[2];
	    for (i=0; i< RARRAY(except)->len; i++) {
		GetOpenFile(rb_io_get_io(RARRAY(except)->ptr[i]), fptr);
		if (FD_ISSET(fileno(fptr->f), ep)) {
		    rb_ary_push(list, RARRAY(except)->ptr[i]);
		}
		else if (fptr->f2 && FD_ISSET(fileno(fptr->f2), ep)) {
		    rb_ary_push(list, RARRAY(except)->ptr[i]);
		}
	    }
	}
    }

    return res;			/* returns an empty array on interrupt */
}

#if !defined(MSDOS) && !defined(__human68k__)
static int
io_cntl(fd,cmd,narg,io_p)
    int fd, cmd, io_p;
    long narg;
{
    int retval;

#ifdef HAVE_FCNTL
    TRAP_BEG;
# if defined(__CYGWIN__)
    retval = io_p?ioctl(fd, cmd, (void*)narg):fcntl(fd, cmd, narg);
# else
    retval = io_p?ioctl(fd, cmd, narg):fcntl(fd, cmd, narg);
# endif
    TRAP_END;
#else
    if (!io_p) {
	rb_notimplement();
    }
    TRAP_BEG;
    retval = ioctl(fd, cmd, narg);
    TRAP_END;
#endif
    return retval;
}
#endif

static VALUE
rb_io_ctl(io, req, arg, io_p)
    VALUE io, req, arg;
    int io_p;
{
#if !defined(MSDOS) && !defined(__human68k__)
    int cmd = NUM2ULONG(req);
    OpenFile *fptr;
    int len = 0;
    long narg = 0;
    int retval;

    rb_secure(2);
    GetOpenFile(io, fptr);

    if (NIL_P(arg) || arg == Qfalse) {
	narg = 0;
    }
    else if (FIXNUM_P(arg)) {
	narg = FIX2INT(arg);
    }
    else if (arg == Qtrue) {
	narg = 1;
    }
    else if (rb_obj_is_kind_of(arg, rb_cInteger)) {
	narg = NUM2LONG(arg);
    }
    else {
	Check_Type(arg, T_STRING);

#ifdef IOCPARM_MASK
#ifndef IOCPARM_LEN
#define IOCPARM_LEN(x)  (((x) >> 16) & IOCPARM_MASK)
#endif
#endif
#ifdef IOCPARM_LEN
	len = IOCPARM_LEN(cmd);	/* on BSDish systems we're safe */
#else
	len = 256;		/* otherwise guess at what's safe */
#endif
	rb_str_modify(arg);

	if (len <= RSTRING(arg)->len) {
	    len = RSTRING(arg)->len;
	}
	if (RSTRING(arg)->len < len) {
	    rb_str_resize(arg, len+1);
	}
	RSTRING(arg)->ptr[len] = 17;	/* a little sanity check here */
	narg = (long)RSTRING(arg)->ptr;
    }
    retval = io_cntl(fileno(fptr->f), cmd, narg, io_p);
    if (retval < 0) rb_sys_fail(fptr->path);
    if (TYPE(arg) == T_STRING && RSTRING(arg)->ptr[len] != 17) {
	rb_raise(rb_eArgError, "return value overflowed string");
    }

    if (fptr->f2) {		/* call on f2 too; ignore result */
	io_cntl(fileno(fptr->f2), cmd, narg, io_p);
    }

    return INT2NUM(retval);
#else
    rb_notimplement();
    return Qnil;		/* not reached */
#endif
}

static VALUE
rb_io_ioctl(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE req, arg;

    rb_scan_args(argc, argv, "11", &req, &arg);
    return rb_io_ctl(io, req, arg, 1);
}

static VALUE
rb_io_fcntl(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
#ifdef HAVE_FCNTL
    VALUE req, arg;

    rb_scan_args(argc, argv, "11", &req, &arg);
    return rb_io_ctl(io, req, arg, 0);
#else
    rb_notimplement();
    return Qnil;		/* not reached */
#endif
}

static VALUE
rb_f_syscall(argc, argv)
    int argc;
    VALUE *argv;
{
#if defined(HAVE_SYSCALL) && !defined(__CHECKER__)
#ifdef atarist
    unsigned long arg[14]; /* yes, we really need that many ! */
#else
    unsigned long arg[8];
#endif
    int retval = -1;
    int i = 1;
    int items = argc - 1;

    /* This probably won't work on machines where sizeof(long) != sizeof(int)
     * or where sizeof(long) != sizeof(char*).  But such machines will
     * not likely have syscall implemented either, so who cares?
     */

    rb_secure(2);
    if (argc == 0)
	rb_raise(rb_eArgError, "too few arguments for syscall");
    arg[0] = NUM2INT(argv[0]); argv++;
    while (items--) {
	if (FIXNUM_P(*argv)) {
	    arg[i] = (unsigned long)NUM2INT(*argv); argv++;
	}
	else {
	    Check_Type(*argv, T_STRING);
	    rb_str_modify(*argv);
	    arg[i] = (unsigned long)RSTRING(*argv)->ptr; argv++;
	}
	i++;
    }
    TRAP_BEG;
    switch (argc) {
      case 1:
	retval = syscall(arg[0]);
	break;
      case 2:
	retval = syscall(arg[0],arg[1]);
	break;
      case 3:
	retval = syscall(arg[0],arg[1],arg[2]);
	break;
      case 4:
	retval = syscall(arg[0],arg[1],arg[2],arg[3]);
	break;
      case 5:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4]);
	break;
      case 6:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5]);
	break;
      case 7:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6]);
	break;
      case 8:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
	  arg[7]);
	break;
#ifdef atarist
      case 9:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
	  arg[7], arg[8]);
	break;
      case 10:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
	  arg[7], arg[8], arg[9]);
	break;
      case 11:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
	  arg[7], arg[8], arg[9], arg[10]);
	break;
      case 12:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
	  arg[7], arg[8], arg[9], arg[10], arg[11]);
	break;
      case 13:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
	  arg[7], arg[8], arg[9], arg[10], arg[11], arg[12]);
	break;
      case 14:
	retval = syscall(arg[0],arg[1],arg[2],arg[3],arg[4],arg[5],arg[6],
	  arg[7], arg[8], arg[9], arg[10], arg[11], arg[12], arg[13]);
	break;
#endif /* atarist */
    }
    TRAP_END;
    if (retval < 0) rb_sys_fail(0);
    return INT2NUM(retval);
#else
    rb_notimplement();
    return Qnil;		/* not reached */
#endif
}

static VALUE
rb_io_s_pipe()
{
#ifndef __human68k__
    int pipes[2];
    VALUE r, w, ary;

#ifdef NT
    if (_pipe(pipes, 1024, O_BINARY) == -1)
#else
    if (pipe(pipes) == -1)
#endif
	rb_sys_fail(0);

    r = prep_stdio(rb_fdopen(pipes[0], "r"), FMODE_READABLE, rb_cIO);
    w = prep_stdio(rb_fdopen(pipes[1], "w"), FMODE_WRITABLE|FMODE_SYNC, rb_cIO);

    return rb_assoc_new(r, w);
#else
    rb_notimplement();
    return Qnil;		/* not reached */
#endif
}

struct foreach_arg {
    int argc;
    VALUE sep;
    VALUE io;
};

static VALUE
rb_io_foreach_line(arg)
    struct foreach_arg *arg;
{
    VALUE str;

    while (!NIL_P(str = rb_io_gets_internal(arg->argc, &arg->sep, arg->io))) {
	rb_yield(str);
    }
    return Qnil;
}

static VALUE
rb_io_s_foreach(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE fname;
    struct foreach_arg arg;

    rb_scan_args(argc, argv, "11", &fname, &arg.sep);
    Check_SafeStr(fname);

    arg.argc = argc - 1;
    arg.io = rb_io_open(RSTRING(fname)->ptr, "r");
    if (NIL_P(arg.io)) return Qnil;
    return rb_ensure(rb_io_foreach_line, (VALUE)&arg, rb_io_close, arg.io);
}

static VALUE
rb_io_readline_line(arg)
    struct foreach_arg *arg;
{
    VALUE line, ary;

    ary = rb_ary_new();
    while (!NIL_P(line = rb_io_gets_internal(arg->argc, &arg->sep, arg->io))) {
	rb_ary_push(ary, line);
    }

    return ary;
}

static VALUE
rb_io_s_readlines(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE fname;
    struct foreach_arg arg;

    rb_scan_args(argc, argv, "11", &fname, &arg.sep);
    Check_SafeStr(fname);

    arg.argc = argc - 1;
    arg.io = rb_io_open(RSTRING(fname)->ptr, "r");
    if (NIL_P(arg.io)) return Qnil;
    return rb_ensure(rb_io_readline_line, (VALUE)&arg, rb_io_close, arg.io);
}

static VALUE
argf_tell()
{
    if (!next_argv()) {
	rb_raise(rb_eArgError, "no stream to tell");
    }

    if (TYPE(current_file) != T_FILE) {
	return argf_forward();
    }
    return rb_io_tell(current_file);
}

static VALUE
argf_seek(argc, argv)
    int argc;
    VALUE *argv;
{
    if (!next_argv()) {
	rb_raise(rb_eArgError, "no stream to seek");
    }

    if (TYPE(current_file) != T_FILE) {
	return argf_forward();
    }
    return rb_io_seek(argc, argv, current_file);
}

static VALUE
argf_set_pos(self, offset)
     VALUE self, offset;
{
    if (!next_argv()) {
	rb_raise(rb_eArgError, "no stream to pos");
    }

    if (TYPE(current_file) != T_FILE) {
	return argf_forward();
    }
    return rb_io_set_pos(current_file, offset);
}

static VALUE
argf_rewind()
{
    if (!next_argv()) {
	rb_raise(rb_eArgError, "no stream to rewind");
    }
    if (TYPE(current_file) != T_FILE) {
	return argf_forward();
    }
    return rb_io_rewind(current_file);
}

static VALUE
argf_fileno()
{
    if (!next_argv()) {
	rb_raise(rb_eArgError, "no stream");
    }
    if (TYPE(current_file) != T_FILE) {
	return argf_forward();
    }
    return rb_io_fileno(current_file);
}

static VALUE
argf_to_io()
{
    next_argv();
    return current_file;
}

static VALUE
argf_read(argc, argv)
    int argc;
    VALUE *argv;
{
    VALUE tmp, str;
    int len;

    if (argc == 1) len = NUM2INT(argv[0]);
    str = Qnil;

  retry:
    if (!next_argv()) return str;
    if (TYPE(current_file) != T_FILE) {
	tmp = argf_forward();
	STR2CSTR(tmp);
    }
    else {
	tmp = io_read(argc, argv, current_file);
    }
    if (NIL_P(tmp) && next_p != -1) {
	any_close(current_file);
	next_p = 1;
	goto retry;
    }
    if (NIL_P(tmp) || RSTRING(tmp)->len == 0) return str;
    else if (NIL_P(str)) str = tmp;
    else rb_str_append(str, tmp);
    if (argc == 0) {
	goto retry;
    }
    if (RSTRING(tmp)->len < len) {
	len -= RSTRING(tmp)->len;
	argv[0] = INT2FIX(len);
	goto retry;
    }

    return str;
}

static VALUE
argf_getc()
{
    VALUE byte;

  retry:
    if (!next_argv()) return Qnil;
    if (TYPE(current_file) != T_FILE) {
	byte = rb_funcall3(current_file, rb_intern("getc"), 0, 0);
    }
    else {
	byte = rb_io_getc(current_file);
    }
    if (NIL_P(byte) && next_p != -1) {
	any_close(current_file);
	next_p = 1;
	goto retry;
    }

    return byte;
}

static VALUE
argf_readchar()
{
    VALUE c = argf_getc();

    if (NIL_P(c)) {
	rb_eof_error();
    }
    return c;
}

static VALUE
argf_eof()
{
    int first = first_p;

    if (!next_argv()) return Qtrue;
    if (!first && next_p == -1) {
	return Qtrue;
    }
    if (TYPE(current_file) != T_FILE) {
	return argf_forward();
    }
    if (rb_io_eof(current_file)) {
	next_p = 1;
	return Qtrue;
    }
    return Qfalse;
}

static VALUE
argf_each_line(argc, argv)
    int argc;
    VALUE *argv;
{
    VALUE str;

    while (RTEST(str = rb_f_gets_internal(argc, argv))) {
	rb_yield(str);
    }
    return argf;
}

static VALUE
argf_each_byte()
{
    VALUE byte;

    while (!NIL_P(byte = argf_getc())) {
	rb_yield(byte);
    }
    return Qnil;
}

static VALUE
argf_filename()
{
    return filename;
}

static VALUE
argf_file()
{
    return current_file;
}

static VALUE
argf_skip()
{
    if (next_p != -1) {
	any_close(current_file);
	next_p = 1;
    }
    return argf;
}

static VALUE
argf_close()
{
    any_close(current_file);
    if (next_p != -1) {
	next_p = 1;
    }
    gets_lineno = 0;
    return argf;
}

static VALUE
argf_closed()
{
    if (TYPE(current_file) != T_FILE) {
	return argf_forward();
    }
    return rb_io_closed(current_file);
}

static VALUE
opt_i_get()
{
    if (!ruby_inplace_mode) return Qnil;
    return rb_str_new2(ruby_inplace_mode);
}

static void
opt_i_set(val)
    VALUE val;
{
    long len;

    if (!RTEST(val)) {
	if (ruby_inplace_mode) free(ruby_inplace_mode);
	ruby_inplace_mode = 0;
	return;
    }
    STR2CSTR(val);
    len = RSTRING(val)->len;
    REALLOC_N(ruby_inplace_mode, char, len + 1);
    ((char *)MEMCPY(ruby_inplace_mode, RSTRING(val)->ptr, char, len))[len] = '\0';
}

void
Init_IO()
{
    rb_eIOError = rb_define_class("IOError", rb_eStandardError);
    rb_eEOFError = rb_define_class("EOFError", rb_eIOError);

    id_write = rb_intern("write");

    rb_define_global_function("syscall", rb_f_syscall, -1);

    rb_define_global_function("open", rb_f_open, -1);
    rb_define_global_function("printf", rb_f_printf, -1);
    rb_define_global_function("print", rb_f_print, -1);
    rb_define_global_function("putc", rb_f_putc, 1);
    rb_define_global_function("puts", rb_f_puts, -1);
    rb_define_global_function("gets", rb_f_gets, -1);
    rb_define_global_function("readline", rb_f_readline, -1);
    rb_define_global_function("getc", rb_f_getc, 0);
    rb_define_global_function("select", rb_f_select, -1);

    rb_define_global_function("readlines", rb_f_readlines, -1);

    rb_define_global_function("`", rb_f_backquote, 1);

    rb_define_global_function("p", rb_f_p, -1);
    rb_define_method(rb_mKernel, "display", rb_obj_display, -1);

    rb_cIO = rb_define_class("IO", rb_cObject);
    rb_include_module(rb_cIO, rb_mEnumerable);

    rb_define_singleton_method(rb_cIO, "new", rb_io_s_new, -1);
    rb_define_method(rb_cIO, "initialize", rb_io_initialize, -1);
    rb_define_singleton_method(rb_cIO, "popen", rb_io_s_popen, -1);
    rb_define_singleton_method(rb_cIO, "foreach", rb_io_s_foreach, -1);
    rb_define_singleton_method(rb_cIO, "readlines", rb_io_s_readlines, -1);
    rb_define_singleton_method(rb_cIO, "select", rb_f_select, -1);
    rb_define_singleton_method(rb_cIO, "pipe", rb_io_s_pipe, 0);

    rb_output_fs = Qnil;
    rb_define_hooked_variable("$,", &rb_output_fs, 0, rb_str_setter);

    rb_rs = rb_default_rs = rb_str_new2("\n"); rb_output_rs = Qnil;
    rb_global_variable(&rb_default_rs);
    OBJ_FREEZE(rb_default_rs);	/* avoid modifying RS_default */
    rb_define_hooked_variable("$/", &rb_rs, 0, rb_str_setter);
    rb_define_hooked_variable("$-0", &rb_rs, 0, rb_str_setter);
    rb_define_hooked_variable("$\\", &rb_output_rs, 0, rb_str_setter);

    rb_define_hooked_variable("$.", &lineno, 0, lineno_setter);
    rb_define_virtual_variable("$_", rb_lastline_get, rb_lastline_set);

    rb_define_method(rb_cIO, "clone", rb_io_clone, 0);
    rb_define_method(rb_cIO, "reopen", rb_io_reopen, -1);

    rb_define_method(rb_cIO, "print", rb_io_print, -1);
    rb_define_method(rb_cIO, "putc", rb_io_putc, 1);
    rb_define_method(rb_cIO, "puts", rb_io_puts, -1);
    rb_define_method(rb_cIO, "printf", rb_io_printf, -1);

    rb_define_method(rb_cIO, "each",  rb_io_each_line, -1);
    rb_define_method(rb_cIO, "each_line",  rb_io_each_line, -1);
    rb_define_method(rb_cIO, "each_byte",  rb_io_each_byte, 0);

    rb_define_method(rb_cIO, "syswrite", rb_io_syswrite, 1);
    rb_define_method(rb_cIO, "sysread",  rb_io_sysread, 1);

    rb_define_method(rb_cIO, "fileno", rb_io_fileno, 0);
    rb_define_alias(rb_cIO, "to_i", "fileno");
    rb_define_method(rb_cIO, "to_io", rb_io_to_io, 0);

    rb_define_method(rb_cIO, "sync",   rb_io_sync, 0);
    rb_define_method(rb_cIO, "sync=",  rb_io_set_sync, 1);

    rb_define_method(rb_cIO, "lineno",   rb_io_lineno, 0);
    rb_define_method(rb_cIO, "lineno=",  rb_io_set_lineno, 1);

    rb_define_method(rb_cIO, "readlines",  rb_io_readlines, -1);

    rb_define_method(rb_cIO, "read",  io_read, -1);
    rb_define_method(rb_cIO, "write", io_write, 1);
    rb_define_method(rb_cIO, "gets",  rb_io_gets_m, -1);
    rb_define_method(rb_cIO, "readline",  rb_io_readline, -1);
    rb_define_method(rb_cIO, "getc",  rb_io_getc, 0);
    rb_define_method(rb_cIO, "readchar",  rb_io_readchar, 0);
    rb_define_method(rb_cIO, "ungetc",rb_io_ungetc, 1);
    rb_define_method(rb_cIO, "<<",    rb_io_addstr, 1);
    rb_define_method(rb_cIO, "flush", rb_io_flush, 0);
    rb_define_method(rb_cIO, "tell", rb_io_tell, 0);
    rb_define_method(rb_cIO, "seek", rb_io_seek, -1);
    rb_define_const(rb_cIO, "SEEK_SET", INT2FIX(SEEK_SET));
    rb_define_const(rb_cIO, "SEEK_CUR", INT2FIX(SEEK_CUR));
    rb_define_const(rb_cIO, "SEEK_END", INT2FIX(SEEK_END));
    rb_define_method(rb_cIO, "rewind", rb_io_rewind, 0);
    rb_define_method(rb_cIO, "pos", rb_io_tell, 0);
    rb_define_method(rb_cIO, "pos=", rb_io_set_pos, 1);
    rb_define_method(rb_cIO, "eof", rb_io_eof, 0);
    rb_define_method(rb_cIO, "eof?", rb_io_eof, 0);

    rb_define_method(rb_cIO, "close", rb_io_close_m, 0);
    rb_define_method(rb_cIO, "closed?", rb_io_closed, 0);
    rb_define_method(rb_cIO, "close_read", rb_io_close_read, 0);
    rb_define_method(rb_cIO, "close_write", rb_io_close_write, 0);

    rb_define_method(rb_cIO, "isatty", rb_io_isatty, 0);
    rb_define_method(rb_cIO, "tty?", rb_io_isatty, 0);
    rb_define_method(rb_cIO, "binmode",  rb_io_binmode, 0);

    rb_define_method(rb_cIO, "ioctl", rb_io_ioctl, -1);
    rb_define_method(rb_cIO, "fcntl", rb_io_fcntl, -1);
    rb_define_method(rb_cIO, "pid", rb_io_pid, 0);

    rb_stdin = orig_stdin = prep_stdio(stdin, FMODE_READABLE, rb_cIO);
    rb_define_hooked_variable("$stdin", &rb_stdin, 0, set_stdin);
    rb_stdout = orig_stdout = prep_stdio(stdout, FMODE_WRITABLE, rb_cIO);
    rb_define_hooked_variable("$stdout", &rb_stdout, 0, set_stdout);
    rb_stderr = orig_stderr = prep_stdio(stderr, FMODE_WRITABLE, rb_cIO);
    rb_define_hooked_variable("$stderr", &rb_stderr, 0, set_stderr);
    rb_defout = rb_stdout;
    rb_define_hooked_variable("$>", &rb_defout, 0, rb_io_defset);
    rb_define_hooked_variable("$defout", &rb_defout, 0, rb_io_defset);

    rb_define_global_const("STDIN", rb_stdin);
    rb_define_global_const("STDOUT", rb_stdout);
    rb_define_global_const("STDERR", rb_stderr);

    argf = rb_obj_alloc(rb_cObject);
    rb_extend_object(argf, rb_mEnumerable);

    rb_define_readonly_variable("$<", &argf);
    rb_define_global_const("ARGF", argf);

    rb_define_singleton_method(argf, "fileno", argf_fileno, 0);
    rb_define_singleton_method(argf, "to_i", argf_fileno, 0);
    rb_define_singleton_method(argf, "to_io", argf_to_io, 0);
    rb_define_singleton_method(argf, "each",  argf_each_line, -1);
    rb_define_singleton_method(argf, "each_line",  argf_each_line, -1);
    rb_define_singleton_method(argf, "each_byte",  argf_each_byte, 0);

    rb_define_singleton_method(argf, "read",  argf_read, -1);
    rb_define_singleton_method(argf, "readlines", rb_f_readlines, -1);
    rb_define_singleton_method(argf, "to_a", rb_f_readlines, -1);
    rb_define_singleton_method(argf, "gets", rb_f_gets, -1);
    rb_define_singleton_method(argf, "readline", rb_f_readline, -1);
    rb_define_singleton_method(argf, "getc", argf_getc, 0);
    rb_define_singleton_method(argf, "readchar", argf_readchar, 0);
    rb_define_singleton_method(argf, "tell", argf_tell, 0);
    rb_define_singleton_method(argf, "seek", argf_seek, -1);
    rb_define_singleton_method(argf, "rewind", argf_rewind, 0);
    rb_define_singleton_method(argf, "pos", argf_tell, 0);
    rb_define_singleton_method(argf, "pos=", argf_set_pos, 1);
    rb_define_singleton_method(argf, "eof", argf_eof, 0);
    rb_define_singleton_method(argf, "eof?", argf_eof, 0);
    rb_define_singleton_method(argf, "binmode", argf_binmode, 0);

    rb_define_singleton_method(argf, "to_s", argf_filename, 0);
    rb_define_singleton_method(argf, "filename", argf_filename, 0);
    rb_define_singleton_method(argf, "file", argf_file, 0);
    rb_define_singleton_method(argf, "skip", argf_skip, 0);
    rb_define_singleton_method(argf, "close", argf_close, 0);
    rb_define_singleton_method(argf, "closed?", argf_closed, 0);

    rb_define_singleton_method(argf, "lineno",   argf_lineno, 0);
    rb_define_singleton_method(argf, "lineno=",  argf_set_lineno, 1);

    current_file = rb_stdin;
    rb_global_variable(&current_file);
    filename = rb_str_new2("-");
    rb_define_readonly_variable("$FILENAME", &filename);

    rb_define_virtual_variable("$-i", opt_i_get, opt_i_set);

#if defined (NT) || defined(DJGPP) || defined(__CYGWIN__) || defined(__human68k__)
    atexit(pipe_atexit);
#endif

    Init_File();

    rb_define_singleton_method(rb_cFile, "open",  rb_file_s_open, -1);
    rb_define_method(rb_cFile, "initialize",  rb_file_initialize, -1);

    rb_file_const("RDONLY", INT2FIX(O_RDONLY));
    rb_file_const("WRONLY", INT2FIX(O_WRONLY));
    rb_file_const("RDWR", INT2FIX(O_RDWR));
    rb_file_const("APPEND", INT2FIX(O_APPEND));
    rb_file_const("CREAT", INT2FIX(O_CREAT));
    rb_file_const("EXCL", INT2FIX(O_EXCL));
#if defined(O_NDELAY) || defined(O_NONBLOCK)
#   ifdef O_NONBLOCK
    rb_file_const("NONBLOCK", INT2FIX(O_NONBLOCK));
#   else
    rb_file_const("NONBLOCK", INT2FIX(O_NDELAY));
#   endif
#endif
    rb_file_const("TRUNC", INT2FIX(O_TRUNC));
#ifdef O_NOCTTY
    rb_file_const("NOCTTY", INT2FIX(O_NOCTTY));
#endif
#ifdef O_BINARY
    rb_file_const("BINARY", INT2FIX(O_BINARY));
#endif
#ifdef O_SYNC
    rb_file_const("SYNC", INT2FIX(O_SYNC));
#endif
}