ruby/ext/pty/pty.c

723 строки
21 KiB
C

#include "ruby/config.h"
#ifdef RUBY_EXTCONF_H
#include RUBY_EXTCONF_H
#endif
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <fcntl.h>
#include <errno.h>
#include <pwd.h>
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_LIBUTIL_H
#include <libutil.h>
#endif
#ifdef HAVE_UTIL_H
#include <util.h>
#endif
#ifdef HAVE_PTY_H
#include <pty.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#else
#define WIFSTOPPED(status) (((status) & 0xff) == 0x7f)
#endif
#include <ctype.h>
#include "ruby/ruby.h"
#include "ruby/io.h"
#include "ruby/util.h"
#include <signal.h>
#ifdef HAVE_SYS_STROPTS_H
#include <sys/stropts.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#define DEVICELEN 16
#ifndef HAVE_SETEUID
# ifdef HAVE_SETREUID
# define seteuid(e) setreuid(-1, (e))
# else /* NOT HAVE_SETREUID */
# ifdef HAVE_SETRESUID
# define seteuid(e) setresuid(-1, (e), -1)
# else /* NOT HAVE_SETRESUID */
/* I can't set euid. (;_;) */
# endif /* HAVE_SETRESUID */
# endif /* HAVE_SETREUID */
#endif /* NO_SETEUID */
static VALUE eChildExited;
/* Returns the exit status of the child for which PTY#check
* raised this exception
*/
static VALUE
echild_status(VALUE self)
{
return rb_ivar_get(self, rb_intern("status"));
}
struct pty_info {
int fd;
rb_pid_t child_pid;
};
static void getDevice(int*, int*, char [DEVICELEN], int);
struct child_info {
int master, slave;
char *slavename;
int argc;
VALUE *argv;
};
static int
chfunc(void *data, char *errbuf, size_t errbuf_len)
{
struct child_info *carg = data;
int master = carg->master;
int slave = carg->slave;
int argc = carg->argc;
VALUE *argv = carg->argv;
#define ERROR_EXIT(str) do { \
strlcpy(errbuf, (str), errbuf_len); \
return -1; \
} while (0)
rb_thread_atfork_before_exec();
/*
* Set free from process group and controlling terminal
*/
#ifdef HAVE_SETSID
(void) setsid();
#else /* HAS_SETSID */
# ifdef HAVE_SETPGRP
# ifdef SETGRP_VOID
if (setpgrp() == -1)
ERROR_EXIT("setpgrp()");
# else /* SETGRP_VOID */
if (setpgrp(0, getpid()) == -1)
ERROR_EXIT("setpgrp()");
{
int i = rb_cloexec_open("/dev/tty", O_RDONLY, 0);
if (i < 0) ERROR_EXIT("/dev/tty");
rb_update_max_fd(i);
if (ioctl(i, TIOCNOTTY, (char *)0))
ERROR_EXIT("ioctl(TIOCNOTTY)");
close(i);
}
# endif /* SETGRP_VOID */
# endif /* HAVE_SETPGRP */
#endif /* HAS_SETSID */
/*
* obtain new controlling terminal
*/
#if defined(TIOCSCTTY)
close(master);
(void) ioctl(slave, TIOCSCTTY, (char *)0);
/* errors ignored for sun */
#else
close(slave);
slave = rb_cloexec_open(carg->slavename, O_RDWR, 0);
if (slave < 0) {
ERROR_EXIT("open: pty slave");
}
rb_update_max_fd(slave);
close(master);
#endif
dup2(slave,0);
dup2(slave,1);
dup2(slave,2);
close(slave);
#if defined(HAVE_SETEUID) || defined(HAVE_SETREUID) || defined(HAVE_SETRESUID)
seteuid(getuid());
#endif
rb_f_exec(argc, argv);
return 0;
#undef ERROR_EXIT
}
static void
establishShell(int argc, VALUE *argv, struct pty_info *info,
char SlaveName[DEVICELEN])
{
int master,slave;
rb_pid_t pid;
char *p, *getenv();
struct passwd *pwent;
VALUE v;
struct child_info carg;
char errbuf[32];
if (argc == 0) {
const char *shellname;
if ((p = getenv("SHELL")) != NULL) {
shellname = p;
}
else {
pwent = getpwuid(getuid());
if (pwent && pwent->pw_shell)
shellname = pwent->pw_shell;
else
shellname = "/bin/sh";
}
v = rb_str_new2(shellname);
argc = 1;
argv = &v;
}
getDevice(&master, &slave, SlaveName, 0);
carg.master = master;
carg.slave = slave;
carg.slavename = SlaveName;
carg.argc = argc;
carg.argv = argv;
errbuf[0] = '\0';
pid = rb_fork_err(0, chfunc, &carg, Qnil, errbuf, sizeof(errbuf));
if (pid < 0) {
int e = errno;
close(master);
close(slave);
errno = e;
rb_sys_fail(errbuf[0] ? errbuf : "fork failed");
}
close(slave);
info->child_pid = pid;
info->fd = master;
}
static int
no_mesg(char *slavedevice, int nomesg)
{
if (nomesg)
return chmod(slavedevice, 0600);
else
return 0;
}
static int
get_device_once(int *master, int *slave, char SlaveName[DEVICELEN], int nomesg, int fail)
{
#if defined(HAVE_POSIX_OPENPT)
/* Unix98 PTY */
int masterfd = -1, slavefd = -1;
char *slavedevice;
struct sigaction dfl, old;
int flags;
dfl.sa_handler = SIG_DFL;
dfl.sa_flags = 0;
sigemptyset(&dfl.sa_mask);
#if defined(__sun) || defined(__FreeBSD__)
/* workaround for Solaris 10: grantpt() doesn't work if FD_CLOEXEC is set. [ruby-dev:44688] */
/* FreeBSD 8 supported O_CLOEXEC for posix_openpt, but FreeBSD 9 removed it.
* http://www.freebsd.org/cgi/query-pr.cgi?pr=162374 */
if ((masterfd = posix_openpt(O_RDWR|O_NOCTTY)) == -1) goto error;
if (sigaction(SIGCHLD, &dfl, &old) == -1) goto error;
if (grantpt(masterfd) == -1) goto grantpt_error;
rb_fd_fix_cloexec(masterfd);
#else
flags = O_RDWR|O_NOCTTY;
# if defined(O_CLOEXEC)
/* glibc posix_openpt() in GNU/Linux calls open("/dev/ptmx", flags) internally.
* So version dependency on GNU/Linux is same as O_CLOEXEC with open().
* O_CLOEXEC is available since Linux 2.6.23. Linux 2.6.18 silently ignore it. */
flags |= O_CLOEXEC;
# endif
if ((masterfd = posix_openpt(flags)) == -1) goto error;
rb_fd_fix_cloexec(masterfd);
if (sigaction(SIGCHLD, &dfl, &old) == -1) goto error;
if (grantpt(masterfd) == -1) goto grantpt_error;
#endif
if (sigaction(SIGCHLD, &old, NULL) == -1) goto error;
if (unlockpt(masterfd) == -1) goto error;
if ((slavedevice = ptsname(masterfd)) == NULL) goto error;
if (no_mesg(slavedevice, nomesg) == -1) goto error;
if ((slavefd = rb_cloexec_open(slavedevice, O_RDWR|O_NOCTTY, 0)) == -1) goto error;
rb_update_max_fd(slavefd);
#if defined(I_PUSH) && !defined(__linux__)
if (ioctl(slavefd, I_PUSH, "ptem") == -1) goto error;
if (ioctl(slavefd, I_PUSH, "ldterm") == -1) goto error;
if (ioctl(slavefd, I_PUSH, "ttcompat") == -1) goto error;
#endif
*master = masterfd;
*slave = slavefd;
strlcpy(SlaveName, slavedevice, DEVICELEN);
return 0;
grantpt_error:
sigaction(SIGCHLD, &old, NULL);
error:
if (slavefd != -1) close(slavefd);
if (masterfd != -1) close(masterfd);
if (fail) {
rb_raise(rb_eRuntimeError, "can't get Master/Slave device");
}
return -1;
#elif defined HAVE_OPENPTY
/*
* Use openpty(3) of 4.3BSD Reno and later,
* or the same interface function.
*/
if (openpty(master, slave, SlaveName,
(struct termios *)0, (struct winsize *)0) == -1) {
if (!fail) return -1;
rb_raise(rb_eRuntimeError, "openpty() failed");
}
rb_fd_fix_cloexec(*master);
rb_fd_fix_cloexec(*slave);
if (no_mesg(SlaveName, nomesg) == -1) {
if (!fail) return -1;
rb_raise(rb_eRuntimeError, "can't chmod slave pty");
}
return 0;
#elif defined HAVE__GETPTY
/* SGI IRIX */
char *name;
mode_t mode = nomesg ? 0600 : 0622;
if (!(name = _getpty(master, O_RDWR, mode, 0))) {
if (!fail) return -1;
rb_raise(rb_eRuntimeError, "_getpty() failed");
}
rb_fd_fix_cloexec(*master);
*slave = rb_cloexec_open(name, O_RDWR, 0);
/* error check? */
rb_update_max_fd(*slave);
strlcpy(SlaveName, name, DEVICELEN);
return 0;
#elif defined(HAVE_PTSNAME)
/* System V */
int masterfd = -1, slavefd = -1;
char *slavedevice;
void (*s)();
extern char *ptsname(int);
extern int unlockpt(int);
extern int grantpt(int);
#if defined(__sun)
/* workaround for Solaris 10: grantpt() doesn't work if FD_CLOEXEC is set. [ruby-dev:44688] */
if((masterfd = open("/dev/ptmx", O_RDWR, 0)) == -1) goto error;
s = signal(SIGCHLD, SIG_DFL);
if(grantpt(masterfd) == -1) goto error;
rb_fd_fix_cloexec(masterfd);
#else
if((masterfd = rb_cloexec_open("/dev/ptmx", O_RDWR, 0)) == -1) goto error;
rb_update_max_fd(masterfd);
s = signal(SIGCHLD, SIG_DFL);
if(grantpt(masterfd) == -1) goto error;
#endif
signal(SIGCHLD, s);
if(unlockpt(masterfd) == -1) goto error;
if((slavedevice = ptsname(masterfd)) == NULL) goto error;
if (no_mesg(slavedevice, nomesg) == -1) goto error;
if((slavefd = rb_cloexec_open(slavedevice, O_RDWR, 0)) == -1) goto error;
rb_update_max_fd(slavefd);
#if defined(I_PUSH) && !defined(__linux__)
if(ioctl(slavefd, I_PUSH, "ptem") == -1) goto error;
if(ioctl(slavefd, I_PUSH, "ldterm") == -1) goto error;
ioctl(slavefd, I_PUSH, "ttcompat");
#endif
*master = masterfd;
*slave = slavefd;
strlcpy(SlaveName, slavedevice, DEVICELEN);
return 0;
error:
if (slavefd != -1) close(slavefd);
if (masterfd != -1) close(masterfd);
if (fail) rb_raise(rb_eRuntimeError, "can't get Master/Slave device");
return -1;
#else
/* BSD */
int masterfd = -1, slavefd = -1;
const char *const *p;
char MasterName[DEVICELEN];
#if defined(__hpux)
static const char MasterDevice[] = "/dev/ptym/pty%s";
static const char SlaveDevice[] = "/dev/pty/tty%s";
static const char *const deviceNo[] = {
"p0","p1","p2","p3","p4","p5","p6","p7",
"p8","p9","pa","pb","pc","pd","pe","pf",
"q0","q1","q2","q3","q4","q5","q6","q7",
"q8","q9","qa","qb","qc","qd","qe","qf",
"r0","r1","r2","r3","r4","r5","r6","r7",
"r8","r9","ra","rb","rc","rd","re","rf",
"s0","s1","s2","s3","s4","s5","s6","s7",
"s8","s9","sa","sb","sc","sd","se","sf",
"t0","t1","t2","t3","t4","t5","t6","t7",
"t8","t9","ta","tb","tc","td","te","tf",
"u0","u1","u2","u3","u4","u5","u6","u7",
"u8","u9","ua","ub","uc","ud","ue","uf",
"v0","v1","v2","v3","v4","v5","v6","v7",
"v8","v9","va","vb","vc","vd","ve","vf",
"w0","w1","w2","w3","w4","w5","w6","w7",
"w8","w9","wa","wb","wc","wd","we","wf",
0
};
#elif defined(_IBMESA) /* AIX/ESA */
static const char MasterDevice[] = "/dev/ptyp%s";
static const char SlaveDevice[] = "/dev/ttyp%s";
static const char *const deviceNo[] = {
"00","01","02","03","04","05","06","07","08","09","0a","0b","0c","0d","0e","0f",
"10","11","12","13","14","15","16","17","18","19","1a","1b","1c","1d","1e","1f",
"20","21","22","23","24","25","26","27","28","29","2a","2b","2c","2d","2e","2f",
"30","31","32","33","34","35","36","37","38","39","3a","3b","3c","3d","3e","3f",
"40","41","42","43","44","45","46","47","48","49","4a","4b","4c","4d","4e","4f",
"50","51","52","53","54","55","56","57","58","59","5a","5b","5c","5d","5e","5f",
"60","61","62","63","64","65","66","67","68","69","6a","6b","6c","6d","6e","6f",
"70","71","72","73","74","75","76","77","78","79","7a","7b","7c","7d","7e","7f",
"80","81","82","83","84","85","86","87","88","89","8a","8b","8c","8d","8e","8f",
"90","91","92","93","94","95","96","97","98","99","9a","9b","9c","9d","9e","9f",
"a0","a1","a2","a3","a4","a5","a6","a7","a8","a9","aa","ab","ac","ad","ae","af",
"b0","b1","b2","b3","b4","b5","b6","b7","b8","b9","ba","bb","bc","bd","be","bf",
"c0","c1","c2","c3","c4","c5","c6","c7","c8","c9","ca","cb","cc","cd","ce","cf",
"d0","d1","d2","d3","d4","d5","d6","d7","d8","d9","da","db","dc","dd","de","df",
"e0","e1","e2","e3","e4","e5","e6","e7","e8","e9","ea","eb","ec","ed","ee","ef",
"f0","f1","f2","f3","f4","f5","f6","f7","f8","f9","fa","fb","fc","fd","fe","ff",
0
};
#else /* 4.2BSD */
static const char MasterDevice[] = "/dev/pty%s";
static const char SlaveDevice[] = "/dev/tty%s";
static const char *const deviceNo[] = {
"p0","p1","p2","p3","p4","p5","p6","p7",
"p8","p9","pa","pb","pc","pd","pe","pf",
"q0","q1","q2","q3","q4","q5","q6","q7",
"q8","q9","qa","qb","qc","qd","qe","qf",
"r0","r1","r2","r3","r4","r5","r6","r7",
"r8","r9","ra","rb","rc","rd","re","rf",
"s0","s1","s2","s3","s4","s5","s6","s7",
"s8","s9","sa","sb","sc","sd","se","sf",
0
};
#endif
for (p = deviceNo; *p != NULL; p++) {
snprintf(MasterName, sizeof MasterName, MasterDevice, *p);
if ((masterfd = rb_cloexec_open(MasterName,O_RDWR,0)) >= 0) {
rb_update_max_fd(masterfd);
*master = masterfd;
snprintf(SlaveName, DEVICELEN, SlaveDevice, *p);
if ((slavefd = rb_cloexec_open(SlaveName,O_RDWR,0)) >= 0) {
rb_update_max_fd(slavefd);
*slave = slavefd;
if (chown(SlaveName, getuid(), getgid()) != 0) goto error;
if (chmod(SlaveName, nomesg ? 0600 : 0622) != 0) goto error;
return 0;
}
close(masterfd);
}
}
error:
if (slavefd != -1) close(slavefd);
if (masterfd != -1) close(masterfd);
if (fail) rb_raise(rb_eRuntimeError, "can't get %s", SlaveName);
return -1;
#endif
}
static void
getDevice(int *master, int *slave, char SlaveName[DEVICELEN], int nomesg)
{
if (get_device_once(master, slave, SlaveName, nomesg, 0)) {
rb_gc();
get_device_once(master, slave, SlaveName, nomesg, 1);
}
}
static VALUE
pty_close_pty(VALUE assoc)
{
VALUE io;
int i;
for (i = 0; i < 2; i++) {
io = rb_ary_entry(assoc, i);
if (TYPE(io) == T_FILE && 0 <= RFILE(io)->fptr->fd)
rb_io_close(io);
}
return Qnil;
}
/*
* call-seq:
* PTY.open => [master_io, slave_file]
* PTY.open {|master_io, slave_file| ... } => block value
*
* Allocates a pty (pseudo-terminal).
*
* In the non-block form, returns a two element array, <tt>[master_io,
* slave_file]</tt>.
*
* In the block form, yields two arguments <tt>master_io, slave_file</tt>
* and the value of the block is returned from +open+.
*
* The IO and File are both closed after the block completes if they haven't
* been already closed.
*
* The arguments in both forms are:
*
* <tt>master_io</tt>:: the master of the pty, as an IO.
* <tt>slave_file</tt>:: the slave of the pty, as a File. The path to the
* terminal device is available via
* <tt>slave_file.path</tt>
*
* === Example
*
* PTY.open {|m, s|
* p m #=> #<IO:masterpty:/dev/pts/1>
* p s #=> #<File:/dev/pts/1>
* p s.path #=> "/dev/pts/1"
* }
*
* # Change the buffering type in factor command,
* # assuming that factor uses stdio for stdout buffering.
* # If IO.pipe is used instead of PTY.open,
* # this code deadlocks because factor's stdout is fully buffered.
* require 'io/console' # for IO#raw!
* m, s = PTY.open
* s.raw! # disable newline conversion.
* r, w = IO.pipe
* pid = spawn("factor", :in=>r, :out=>s)
* r.close
* s.close
* w.puts "42"
* p m.gets #=> "42: 2 3 7\n"
* w.puts "144"
* p m.gets #=> "144: 2 2 2 2 3 3\n"
* w.close
* # The result of read operation when pty slave is closed is platform
* # dependent.
* ret = begin
* m.gets # FreeBSD returns nil.
* rescue Errno::EIO # GNU/Linux raises EIO.
* nil
* end
* p ret #=> nil
*
*/
static VALUE
pty_open(VALUE klass)
{
int master_fd, slave_fd;
char slavename[DEVICELEN];
VALUE master_io, slave_file;
rb_io_t *master_fptr, *slave_fptr;
VALUE assoc;
getDevice(&master_fd, &slave_fd, slavename, 1);
master_io = rb_obj_alloc(rb_cIO);
MakeOpenFile(master_io, master_fptr);
master_fptr->mode = FMODE_READWRITE | FMODE_SYNC | FMODE_DUPLEX;
master_fptr->fd = master_fd;
master_fptr->pathv = rb_obj_freeze(rb_sprintf("masterpty:%s", slavename));
slave_file = rb_obj_alloc(rb_cFile);
MakeOpenFile(slave_file, slave_fptr);
slave_fptr->mode = FMODE_READWRITE | FMODE_SYNC | FMODE_DUPLEX | FMODE_TTY;
slave_fptr->fd = slave_fd;
slave_fptr->pathv = rb_obj_freeze(rb_str_new_cstr(slavename));
assoc = rb_assoc_new(master_io, slave_file);
if (rb_block_given_p()) {
return rb_ensure(rb_yield, assoc, pty_close_pty, assoc);
}
return assoc;
}
static VALUE
pty_detach_process(struct pty_info *info)
{
rb_detach_process(info->child_pid);
return Qnil;
}
/*
* call-seq:
* PTY.spawn(command_line) { |r, w, pid| ... }
* PTY.spawn(command_line) => [r, w, pid]
* PTY.spawn(command, args, ...) { |r, w, pid| ... }
* PTY.spawn(command, args, ...) => [r, w, pid]
* PTY.getpty(command_line) { |r, w, pid| ... }
* PTY.getpty(command_line) => [r, w, pid]
* PTY.getpty(command, args, ...) { |r, w, pid| ... }
* PTY.getpty(command, args, ...) => [r, w, pid]
*
* Spawns the specified command on a newly allocated pty.
*
* The command's controlling tty is set to the slave device of the pty
* and its standard input/output/error is redirected to the slave device.
*
* <tt>command_line</tt>:: The full command line to run
* <tt>command</tt>:: The command to run, as a String.
* <tt>args</tt>:: Zero or more arguments, as Strings, representing
* the arguments to +command+
*
* In the non-block form this returns an array of size three,
* <tt>[r, w, pid]</tt>. In the block form the block will be called with
* these as arguments, <tt>|r,w,pid|</tt>:
*
* +r+:: An IO that can be read from that contains the command's
* standard output and standard error
* +w+:: An IO that can be written to that is the command's
* standard input
* +pid+:: The process identifier for the command.
*/
static VALUE
pty_getpty(int argc, VALUE *argv, VALUE self)
{
VALUE res;
struct pty_info info;
rb_io_t *wfptr,*rfptr;
VALUE rport = rb_obj_alloc(rb_cFile);
VALUE wport = rb_obj_alloc(rb_cFile);
char SlaveName[DEVICELEN];
MakeOpenFile(rport, rfptr);
MakeOpenFile(wport, wfptr);
establishShell(argc, argv, &info, SlaveName);
rfptr->mode = rb_io_mode_flags("r");
rfptr->fd = info.fd;
rfptr->pathv = rb_obj_freeze(rb_str_new_cstr(SlaveName));
wfptr->mode = rb_io_mode_flags("w") | FMODE_SYNC;
wfptr->fd = rb_cloexec_dup(info.fd);
if (wfptr->fd == -1)
rb_sys_fail("dup()");
rb_update_max_fd(wfptr->fd);
wfptr->pathv = rfptr->pathv;
res = rb_ary_new2(3);
rb_ary_store(res,0,(VALUE)rport);
rb_ary_store(res,1,(VALUE)wport);
rb_ary_store(res,2,PIDT2NUM(info.child_pid));
if (rb_block_given_p()) {
rb_ensure(rb_yield, res, pty_detach_process, (VALUE)&info);
return Qnil;
}
return res;
}
NORETURN(static void raise_from_check(pid_t pid, int status));
static void
raise_from_check(pid_t pid, int status)
{
const char *state;
char buf[1024];
VALUE exc;
#if defined(WIFSTOPPED)
#elif defined(IF_STOPPED)
#define WIFSTOPPED(status) IF_STOPPED(status)
#else
---->> Either IF_STOPPED or WIFSTOPPED is needed <<----
#endif /* WIFSTOPPED | IF_STOPPED */
if (WIFSTOPPED(status)) { /* suspend */
state = "stopped";
}
else if (kill(pid, 0) == 0) {
state = "changed";
}
else {
state = "exited";
}
snprintf(buf, sizeof(buf), "pty - %s: %ld", state, (long)pid);
exc = rb_exc_new2(eChildExited, buf);
rb_iv_set(exc, "status", rb_last_status_get());
rb_exc_raise(exc);
}
/*
* call-seq:
* PTY.check(pid, raise = false) => Process::Status or nil
* PTY.check(pid, true) => nil or raises PTY::ChildExited
*
* Checks the status of the child process specified by +pid+.
* Returns +nil+ if the process is still alive. If the process
* is not alive, will return a <tt>Process::Status</tt> or raise
* a <tt>PTY::ChildExited</tt> (if +raise+ was true).
*
* +pid+:: The process id of the process to check
* +raise+:: If true and the process identified by +pid+ is no longer
* alive a <tt>PTY::ChildExited</tt> is raised.
*
* Returns nil or a <tt>Process::Status</tt> when +raise+ is false.
*/
static VALUE
pty_check(int argc, VALUE *argv, VALUE self)
{
VALUE pid, exc;
pid_t cpid;
int status;
rb_scan_args(argc, argv, "11", &pid, &exc);
cpid = rb_waitpid(NUM2PIDT(pid), &status, WNOHANG|WUNTRACED);
if (cpid == -1 || cpid == 0) return Qnil;
if (!RTEST(exc)) return rb_last_status_get();
raise_from_check(cpid, status);
UNREACHABLE;
}
static VALUE cPTY;
/*
* Document-class: PTY::ChildExited
*
* Thrown when PTY#check is called for a pid that represents a process that
* has exited.
*/
/*
* Document-class: PTY
*
* Creates and managed pseudo terminals (PTYs). See also
* http://en.wikipedia.org/wiki/Pseudo_terminal
*/
void
Init_pty()
{
cPTY = rb_define_module("PTY");
rb_define_module_function(cPTY,"getpty",pty_getpty,-1);
rb_define_module_function(cPTY,"spawn",pty_getpty,-1);
rb_define_singleton_method(cPTY,"check",pty_check,-1);
rb_define_singleton_method(cPTY,"open",pty_open,0);
eChildExited = rb_define_class_under(cPTY,"ChildExited",rb_eRuntimeError);
rb_define_method(eChildExited,"status",echild_status,0);
}