1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2022-11-09 12:17:21 -05:00
ruby--ruby/ext/io/console/console.c
nobu 755f669316 io/console: rdoc
* ext/io/console/console.c (io_getch): add rdoc.

* ext/io/console/lib/console/size.rb (IO.console_size): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40911 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2013-05-24 06:54:25 +00:00

815 lines
18 KiB
C

/* -*- c-file-style: "ruby" -*- */
/*
* console IO module
*/
#include "ruby.h"
#ifdef HAVE_RUBY_IO_H
#include "ruby/io.h"
#else
#include "rubyio.h"
/* assumes rb_io_t doesn't have pathv */
#include "util.h" /* for ruby_strdup() */
#endif
#ifndef HAVE_RB_IO_T
typedef OpenFile rb_io_t;
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifndef RB_TYPE_P
#define RB_TYPE_P(obj, type) (TYPE(obj) == type)
#endif
#if defined HAVE_TERMIOS_H
# include <termios.h>
typedef struct termios conmode;
static int
setattr(int fd, conmode *t)
{
while (tcsetattr(fd, TCSAFLUSH, t)) {
if (errno != EINTR) return 0;
}
return 1;
}
# define getattr(fd, t) (tcgetattr(fd, t) == 0)
#elif defined HAVE_TERMIO_H
# include <termio.h>
typedef struct termio conmode;
# define setattr(fd, t) (ioctl(fd, TCSETAF, t) == 0)
# define getattr(fd, t) (ioctl(fd, TCGETA, t) == 0)
#elif defined HAVE_SGTTY_H
# include <sgtty.h>
typedef struct sgttyb conmode;
# ifdef HAVE_STTY
# define setattr(fd, t) (stty(fd, t) == 0)
# else
# define setattr(fd, t) (ioctl((fd), TIOCSETP, (t)) == 0)
# endif
# ifdef HAVE_GTTY
# define getattr(fd, t) (gtty(fd, t) == 0)
# else
# define getattr(fd, t) (ioctl((fd), TIOCGETP, (t)) == 0)
# endif
#elif defined _WIN32
#include <winioctl.h>
typedef DWORD conmode;
#ifdef HAVE_RB_W32_MAP_ERRNO
#define LAST_ERROR rb_w32_map_errno(GetLastError())
#else
#define LAST_ERROR EBADF
#endif
#define SET_LAST_ERROR (errno = LAST_ERROR, 0)
static int
setattr(int fd, conmode *t)
{
int x = SetConsoleMode((HANDLE)rb_w32_get_osfhandle(fd), *t);
if (!x) errno = LAST_ERROR;
return x;
}
static int
getattr(int fd, conmode *t)
{
int x = GetConsoleMode((HANDLE)rb_w32_get_osfhandle(fd), t);
if (!x) errno = LAST_ERROR;
return x;
}
#endif
#ifndef SET_LAST_ERROR
#define SET_LAST_ERROR (0)
#endif
#ifndef InitVM
#define InitVM(ext) {void InitVM_##ext(void);InitVM_##ext();}
#endif
static ID id_getc, id_console;
typedef struct {
int vmin;
int vtime;
} rawmode_arg_t;
static rawmode_arg_t *
rawmode_opt(int argc, VALUE *argv, rawmode_arg_t *opts)
{
rawmode_arg_t *optp = NULL;
VALUE vopts;
#ifdef HAVE_RB_SCAN_ARGS_OPTIONAL_HASH
rb_scan_args(argc, argv, "0:", &vopts);
#else
vopts = Qnil;
if (argc > 0) {
vopts = argv[--argc];
if (!NIL_P(vopts)) {
# ifdef HAVE_RB_CHECK_HASH_TYPE
vopts = rb_check_hash_type(vopts);
if (NIL_P(vopts)) ++argc;
# else
Check_Type(vopts, T_HASH);
# endif
}
}
rb_scan_args(argc, argv, "0");
#endif
if (!NIL_P(vopts)) {
VALUE vmin = rb_hash_aref(vopts, ID2SYM(rb_intern("min")));
VALUE vtime = rb_hash_aref(vopts, ID2SYM(rb_intern("time")));
/* default values by `stty raw` */
opts->vmin = 1;
opts->vtime = 0;
if (!NIL_P(vmin)) {
opts->vmin = NUM2INT(vmin);
optp = opts;
}
if (!NIL_P(vtime)) {
VALUE v10 = INT2FIX(10);
vtime = rb_funcall3(vtime, '*', 1, &v10);
opts->vtime = NUM2INT(vtime);
optp = opts;
}
}
return optp;
}
static void
set_rawmode(conmode *t, void *arg)
{
#ifdef HAVE_CFMAKERAW
cfmakeraw(t);
t->c_lflag &= ~(ECHOE|ECHOK);
#elif defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
t->c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL|IXON);
t->c_oflag &= ~OPOST;
t->c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|ICANON|ISIG|IEXTEN);
t->c_cflag &= ~(CSIZE|PARENB);
t->c_cflag |= CS8;
#elif defined HAVE_SGTTY_H
t->sg_flags &= ~ECHO;
t->sg_flags |= RAW;
#elif defined _WIN32
*t = 0;
#endif
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
if (arg) {
const rawmode_arg_t *r = arg;
if (r->vmin >= 0) t->c_cc[VMIN] = r->vmin;
if (r->vtime >= 0) t->c_cc[VTIME] = r->vtime;
}
#endif
}
static void
set_cookedmode(conmode *t, void *arg)
{
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
t->c_iflag |= (BRKINT|ISTRIP|ICRNL|IXON);
t->c_oflag |= OPOST;
t->c_lflag |= (ECHO|ECHOE|ECHOK|ECHONL|ICANON|ISIG|IEXTEN);
#elif defined HAVE_SGTTY_H
t->sg_flags |= ECHO;
t->sg_flags &= ~RAW;
#elif defined _WIN32
*t |= ENABLE_ECHO_INPUT|ENABLE_LINE_INPUT|ENABLE_PROCESSED_INPUT;
#endif
}
static void
set_noecho(conmode *t, void *arg)
{
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
t->c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
#elif defined HAVE_SGTTY_H
t->sg_flags &= ~ECHO;
#elif defined _WIN32
*t &= ~ENABLE_ECHO_INPUT;
#endif
}
static void
set_echo(conmode *t, void *arg)
{
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
t->c_lflag |= (ECHO | ECHOE | ECHOK | ECHONL);
#elif defined HAVE_SGTTY_H
t->sg_flags |= ECHO;
#elif defined _WIN32
*t |= ENABLE_ECHO_INPUT;
#endif
}
static int
echo_p(conmode *t)
{
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
return (t->c_lflag & (ECHO | ECHONL)) != 0;
#elif defined HAVE_SGTTY_H
return (t->sg_flags & ECHO) != 0;
#elif defined _WIN32
return (*t & ENABLE_ECHO_INPUT) != 0;
#endif
}
static int
set_ttymode(int fd, conmode *t, void (*setter)(conmode *, void *), void *arg)
{
conmode r;
if (!getattr(fd, t)) return 0;
r = *t;
setter(&r, arg);
return setattr(fd, &r);
}
#ifdef GetReadFile
#define GetReadFD(fptr) fileno(GetReadFile(fptr))
#else
#define GetReadFD(fptr) ((fptr)->fd)
#endif
#ifdef GetWriteFile
#define GetWriteFD(fptr) fileno(GetWriteFile(fptr))
#else
static inline int
get_write_fd(const rb_io_t *fptr)
{
VALUE wio = fptr->tied_io_for_writing;
rb_io_t *ofptr;
if (!wio) return fptr->fd;
GetOpenFile(wio, ofptr);
return ofptr->fd;
}
#define GetWriteFD(fptr) get_write_fd(fptr)
#endif
#define FD_PER_IO 2
static VALUE
ttymode(VALUE io, VALUE (*func)(VALUE), void (*setter)(conmode *, void *), void *arg)
{
rb_io_t *fptr;
int status = -1;
int error = 0;
int fd[FD_PER_IO];
conmode t[FD_PER_IO];
VALUE result = Qnil;
GetOpenFile(io, fptr);
fd[0] = GetReadFD(fptr);
if (fd[0] != -1) {
if (set_ttymode(fd[0], t+0, setter, arg)) {
status = 0;
}
else {
error = errno;
fd[0] = -1;
}
}
fd[1] = GetWriteFD(fptr);
if (fd[1] != -1 && fd[1] != fd[0]) {
if (set_ttymode(fd[1], t+1, setter, arg)) {
status = 0;
}
else {
error = errno;
fd[1] = -1;
}
}
if (status == 0) {
result = rb_protect(func, io, &status);
}
GetOpenFile(io, fptr);
if (fd[0] != -1 && fd[0] == GetReadFD(fptr)) {
if (!setattr(fd[0], t+0)) {
error = errno;
status = -1;
}
}
if (fd[1] != -1 && fd[1] != fd[0] && fd[1] == GetWriteFD(fptr)) {
if (!setattr(fd[1], t+1)) {
error = errno;
status = -1;
}
}
if (status) {
if (status == -1) {
errno = error;
rb_sys_fail(0);
}
rb_jump_tag(status);
}
return result;
}
/*
* call-seq:
* io.raw(min: nil, time: nil) {|io| }
*
* Yields +self+ within raw mode.
*
* STDIN.raw(&:gets)
*
* will read and return a line without echo back and line editing.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_raw(int argc, VALUE *argv, VALUE io)
{
rawmode_arg_t opts, *optp = rawmode_opt(argc, argv, &opts);
return ttymode(io, rb_yield, set_rawmode, optp);
}
/*
* call-seq:
* io.raw!(min: nil, time: nil)
*
* Enables raw mode.
*
* If the terminal mode needs to be back, use io.raw { ... }.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_set_raw(int argc, VALUE *argv, VALUE io)
{
conmode t;
rb_io_t *fptr;
int fd;
rawmode_arg_t opts, *optp = rawmode_opt(argc, argv, &opts);
GetOpenFile(io, fptr);
fd = GetReadFD(fptr);
if (!getattr(fd, &t)) rb_sys_fail(0);
set_rawmode(&t, optp);
if (!setattr(fd, &t)) rb_sys_fail(0);
return io;
}
/*
* call-seq:
* io.cooked {|io| }
*
* Yields +self+ within cooked mode.
*
* STDIN.cooked(&:gets)
*
* will read and return a line with echo back and line editing.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_cooked(VALUE io)
{
return ttymode(io, rb_yield, set_cookedmode, NULL);
}
/*
* call-seq:
* io.cooked!
*
* Enables cooked mode.
*
* If the terminal mode needs to be back, use io.cooked { ... }.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_set_cooked(VALUE io)
{
conmode t;
rb_io_t *fptr;
int fd;
GetOpenFile(io, fptr);
fd = GetReadFD(fptr);
if (!getattr(fd, &t)) rb_sys_fail(0);
set_cookedmode(&t, NULL);
if (!setattr(fd, &t)) rb_sys_fail(0);
return io;
}
static VALUE
getc_call(VALUE io)
{
return rb_funcall2(io, id_getc, 0, 0);
}
/*
* call-seq:
* io.getch(min: nil, time: nil) -> char
*
* Reads and returns a character in raw mode.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_getch(int argc, VALUE *argv, VALUE io)
{
rawmode_arg_t opts, *optp = rawmode_opt(argc, argv, &opts);
return ttymode(io, getc_call, set_rawmode, optp);
}
/*
* call-seq:
* io.noecho {|io| }
*
* Yields +self+ with disabling echo back.
*
* STDIN.noecho(&:gets)
*
* will read and return a line without echo back.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_noecho(VALUE io)
{
return ttymode(io, rb_yield, set_noecho, NULL);
}
/*
* call-seq:
* io.echo = flag
*
* Enables/disables echo back.
* On some platforms, all combinations of this flags and raw/cooked
* mode may not be valid.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_set_echo(VALUE io, VALUE f)
{
conmode t;
rb_io_t *fptr;
int fd;
GetOpenFile(io, fptr);
fd = GetReadFD(fptr);
if (!getattr(fd, &t)) rb_sys_fail(0);
if (RTEST(f))
set_echo(&t, NULL);
else
set_noecho(&t, NULL);
if (!setattr(fd, &t)) rb_sys_fail(0);
return io;
}
/*
* call-seq:
* io.echo? -> true or false
*
* Returns +true+ if echo back is enabled.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_echo_p(VALUE io)
{
conmode t;
rb_io_t *fptr;
int fd;
GetOpenFile(io, fptr);
fd = GetReadFD(fptr);
if (!getattr(fd, &t)) rb_sys_fail(0);
return echo_p(&t) ? Qtrue : Qfalse;
}
#if defined TIOCGWINSZ
typedef struct winsize rb_console_size_t;
#define getwinsize(fd, buf) (ioctl((fd), TIOCGWINSZ, (buf)) == 0)
#define setwinsize(fd, buf) (ioctl((fd), TIOCSWINSZ, (buf)) == 0)
#define winsize_row(buf) (buf)->ws_row
#define winsize_col(buf) (buf)->ws_col
#elif defined _WIN32
typedef CONSOLE_SCREEN_BUFFER_INFO rb_console_size_t;
#define getwinsize(fd, buf) ( \
GetConsoleScreenBufferInfo((HANDLE)rb_w32_get_osfhandle(fd), (buf)) || \
SET_LAST_ERROR)
#define winsize_row(buf) ((buf)->srWindow.Bottom - (buf)->srWindow.Top + 1)
#define winsize_col(buf) (buf)->dwSize.X
#endif
#if defined TIOCGWINSZ || defined _WIN32
#define USE_CONSOLE_GETSIZE 1
#endif
#ifdef USE_CONSOLE_GETSIZE
/*
* call-seq:
* io.winsize -> [rows, columns]
*
* Returns console size.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_winsize(VALUE io)
{
rb_io_t *fptr;
int fd;
rb_console_size_t ws;
GetOpenFile(io, fptr);
fd = GetWriteFD(fptr);
if (!getwinsize(fd, &ws)) rb_sys_fail(0);
return rb_assoc_new(INT2NUM(winsize_row(&ws)), INT2NUM(winsize_col(&ws)));
}
/*
* call-seq:
* io.winsize = [rows, columns]
*
* Tries to set console size. The effect depends on the platform and
* the running environment.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_set_winsize(VALUE io, VALUE size)
{
rb_io_t *fptr;
rb_console_size_t ws;
#if defined _WIN32
HANDLE wh;
int newrow, newcol;
#endif
VALUE row, col, xpixel, ypixel;
#if defined TIOCSWINSZ
int fd;
#endif
GetOpenFile(io, fptr);
size = rb_Array(size);
rb_scan_args((int)RARRAY_LEN(size), RARRAY_PTR(size), "22",
&row, &col, &xpixel, &ypixel);
#if defined TIOCSWINSZ
fd = GetWriteFD(fptr);
ws.ws_row = ws.ws_col = ws.ws_xpixel = ws.ws_ypixel = 0;
#define SET(m) ws.ws_##m = NIL_P(m) ? 0 : (unsigned short)NUM2UINT(m)
SET(row);
SET(col);
SET(xpixel);
SET(ypixel);
#undef SET
if (!setwinsize(fd, &ws)) rb_sys_fail(0);
#elif defined _WIN32
wh = (HANDLE)rb_w32_get_osfhandle(GetReadFD(fptr));
newrow = (SHORT)NUM2UINT(row);
newcol = (SHORT)NUM2UINT(col);
if (!getwinsize(GetReadFD(fptr), &ws)) {
rb_sys_fail("GetConsoleScreenBufferInfo");
}
if ((ws.dwSize.X < newcol && (ws.dwSize.X = newcol, 1)) ||
(ws.dwSize.Y < newrow && (ws.dwSize.Y = newrow, 1))) {
if (!(SetConsoleScreenBufferSize(wh, ws.dwSize) || SET_LAST_ERROR)) {
rb_sys_fail("SetConsoleScreenBufferInfo");
}
}
ws.srWindow.Left = 0;
ws.srWindow.Top = 0;
ws.srWindow.Right = newcol;
ws.srWindow.Bottom = newrow;
if (!(SetConsoleWindowInfo(wh, FALSE, &ws.srWindow) || SET_LAST_ERROR)) {
rb_sys_fail("SetConsoleWindowInfo");
}
#endif
return io;
}
#endif
/*
* call-seq:
* io.iflush
*
* Flushes input buffer in kernel.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_iflush(VALUE io)
{
rb_io_t *fptr;
int fd;
GetOpenFile(io, fptr);
fd = GetReadFD(fptr);
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
if (tcflush(fd, TCIFLUSH)) rb_sys_fail(0);
#endif
(void)fd;
return io;
}
/*
* call-seq:
* io.oflush
*
* Flushes output buffer in kernel.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_oflush(VALUE io)
{
rb_io_t *fptr;
int fd;
GetOpenFile(io, fptr);
fd = GetWriteFD(fptr);
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
if (tcflush(fd, TCOFLUSH)) rb_sys_fail(0);
#endif
(void)fd;
return io;
}
/*
* call-seq:
* io.ioflush
*
* Flushes input and output buffers in kernel.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_ioflush(VALUE io)
{
rb_io_t *fptr;
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
int fd1, fd2;
#endif
GetOpenFile(io, fptr);
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
fd1 = GetReadFD(fptr);
fd2 = GetWriteFD(fptr);
if (fd2 != -1 && fd1 != fd2) {
if (tcflush(fd1, TCIFLUSH)) rb_sys_fail(0);
if (tcflush(fd2, TCOFLUSH)) rb_sys_fail(0);
}
else {
if (tcflush(fd1, TCIOFLUSH)) rb_sys_fail(0);
}
#endif
return io;
}
#ifndef HAVE_RB_CLOEXEC_OPEN
static int
rb_cloexec_open(const char *pathname, int flags, mode_t mode)
{
int ret;
#ifdef O_CLOEXEC
/* O_CLOEXEC is available since Linux 2.6.23. Linux 2.6.18 silently ignore it. */
flags |= O_CLOEXEC;
#elif defined O_NOINHERIT
flags |= O_NOINHERIT;
#endif
return open(pathname, flags, mode);
}
#define rb_update_max_fd(fd) (void)(fd)
#endif
/*
* call-seq:
* IO.console -> #<File:/dev/tty>
*
* Returns an File instance opened console.
*
* You must require 'io/console' to use this method.
*/
static VALUE
console_dev(VALUE klass)
{
VALUE con = 0;
rb_io_t *fptr;
if (klass == rb_cIO) klass = rb_cFile;
if (rb_const_defined(klass, id_console)) {
con = rb_const_get(klass, id_console);
if (RB_TYPE_P(con, T_FILE)) {
if ((fptr = RFILE(con)->fptr) && GetReadFD(fptr) != -1)
return con;
}
rb_mod_remove_const(klass, ID2SYM(id_console));
}
{
VALUE args[2];
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H || defined HAVE_SGTTY_H
# define CONSOLE_DEVICE "/dev/tty"
#elif defined _WIN32
# define CONSOLE_DEVICE "con$"
# define CONSOLE_DEVICE_FOR_READING "conin$"
# define CONSOLE_DEVICE_FOR_WRITING "conout$"
#endif
#ifndef CONSOLE_DEVICE_FOR_READING
# define CONSOLE_DEVICE_FOR_READING CONSOLE_DEVICE
#endif
#ifdef CONSOLE_DEVICE_FOR_WRITING
VALUE out;
rb_io_t *ofptr;
#endif
int fd;
#ifdef CONSOLE_DEVICE_FOR_WRITING
fd = rb_cloexec_open(CONSOLE_DEVICE_FOR_WRITING, O_WRONLY, 0);
if (fd < 0) return Qnil;
rb_update_max_fd(fd);
args[1] = INT2FIX(O_WRONLY);
args[0] = INT2NUM(fd);
out = rb_class_new_instance(2, args, klass);
#endif
fd = rb_cloexec_open(CONSOLE_DEVICE_FOR_READING, O_RDWR, 0);
if (fd < 0) {
#ifdef CONSOLE_DEVICE_FOR_WRITING
rb_io_close(out);
#endif
return Qnil;
}
rb_update_max_fd(fd);
args[1] = INT2FIX(O_RDWR);
args[0] = INT2NUM(fd);
con = rb_class_new_instance(2, args, klass);
GetOpenFile(con, fptr);
#ifdef HAVE_RUBY_IO_H
fptr->pathv = rb_obj_freeze(rb_str_new2(CONSOLE_DEVICE));
#else
fptr->path = ruby_strdup(CONSOLE_DEVICE);
#endif
#ifdef CONSOLE_DEVICE_FOR_WRITING
GetOpenFile(out, ofptr);
# ifdef HAVE_RB_IO_GET_WRITE_IO
ofptr->pathv = fptr->pathv;
fptr->tied_io_for_writing = out;
# else
fptr->f2 = ofptr->f;
ofptr->f = 0;
# endif
ofptr->mode |= FMODE_SYNC;
#endif
fptr->mode |= FMODE_SYNC;
rb_const_set(klass, id_console, con);
}
return con;
}
/*
* call-seq:
* io.getch(min: nil, time: nil) -> char
*
* See IO#getch.
*/
static VALUE
io_getch(int argc, VALUE *argv, VALUE io)
{
return rb_funcall2(io, rb_intern("getc"), argc, argv);
}
/*
* IO console methods
*/
void
Init_console(void)
{
id_getc = rb_intern("getc");
id_console = rb_intern("console");
InitVM(console);
}
void
InitVM_console(void)
{
rb_define_method(rb_cIO, "raw", console_raw, -1);
rb_define_method(rb_cIO, "raw!", console_set_raw, -1);
rb_define_method(rb_cIO, "cooked", console_cooked, 0);
rb_define_method(rb_cIO, "cooked!", console_set_cooked, 0);
rb_define_method(rb_cIO, "getch", console_getch, -1);
rb_define_method(rb_cIO, "echo=", console_set_echo, 1);
rb_define_method(rb_cIO, "echo?", console_echo_p, 0);
rb_define_method(rb_cIO, "noecho", console_noecho, 0);
rb_define_method(rb_cIO, "winsize", console_winsize, 0);
rb_define_method(rb_cIO, "winsize=", console_set_winsize, 1);
rb_define_method(rb_cIO, "iflush", console_iflush, 0);
rb_define_method(rb_cIO, "oflush", console_oflush, 0);
rb_define_method(rb_cIO, "ioflush", console_ioflush, 0);
rb_define_singleton_method(rb_cIO, "console", console_dev, 0);
{
VALUE mReadable = rb_define_module_under(rb_cIO, "generic_readable");
rb_define_method(mReadable, "getch", io_getch, -1);
}
}