Add 'mrbgems/mruby-io/' from commit '3c8e1f94c44252c836f79a48bb17726da28e2756'

git-subtree-dir: mrbgems/mruby-io
git-subtree-mainline: 10ed730e4bd921cf4d8fe6f6d2e3cb3f0840f3b7
git-subtree-split: 3c8e1f94c44252c836f79a48bb17726da28e2756

1 files changed, 1114 insertions, 0 deletions

diff --git a/mrbgems/mruby-io/src/io.c b/mrbgems/mruby-io/src/io.c
new file mode 100644
index 000000000..8792bb2aa
--- /dev/null
+++ b/mrbgems/mruby-io/src/io.c
@@ -0,0 +1,1114 @@
+/*
+** io.c - IO class
+*/
+
+#include "mruby.h"
+#include "mruby/array.h"
+#include "mruby/class.h"
+#include "mruby/data.h"
+#include "mruby/hash.h"
+#include "mruby/string.h"
+#include "mruby/variable.h"
+#include "mruby/ext/io.h"
+
+#if MRUBY_RELEASE_NO < 10000
+#include "error.h"
+#else
+#include "mruby/error.h"
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#if defined(_WIN32) || defined(_WIN64)
+  #include <winsock.h>
+  #include <io.h>
+  #define open  _open
+  #define close _close
+  #define read  _read
+  #define write _write
+  #define lseek _lseek
+#else
+  #include <sys/wait.h>
+  #include <unistd.h>
+#endif
+
+#include <fcntl.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+
+static void mrb_io_free(mrb_state *mrb, void *ptr);
+struct mrb_data_type mrb_io_type = { "IO", mrb_io_free };
+
+
+static struct mrb_io *io_get_open_fptr(mrb_state *mrb, mrb_value self);
+static int mrb_io_modestr_to_flags(mrb_state *mrb, const char *modestr);
+static int mrb_io_flags_to_modenum(mrb_state *mrb, int flags);
+static void fptr_finalize(mrb_state *mrb, struct mrb_io *fptr, int quiet);
+
+#if MRUBY_RELEASE_NO < 10000
+static struct RClass *
+mrb_module_get(mrb_state *mrb, const char *name)
+{
+  return mrb_class_get(mrb, name);
+}
+#endif
+
+static struct mrb_io *
+io_get_open_fptr(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_io *fptr;
+
+  fptr = (struct mrb_io *)mrb_get_datatype(mrb, self, &mrb_io_type);
+  if (fptr->fd < 0) {
+    mrb_raise(mrb, E_IO_ERROR, "closed stream.");
+  }
+  return fptr;
+}
+
+#if !defined(_WIN32) && !defined(_WIN64)
+static void
+io_set_process_status(mrb_state *mrb, pid_t pid, int status)
+{
+  struct RClass *c_process, *c_status;
+  mrb_value v;
+
+  c_status = NULL;
+  if (mrb_class_defined(mrb, "Process")) {
+    c_process = mrb_module_get(mrb, "Process");
+    if (mrb_const_defined(mrb, mrb_obj_value(c_process), mrb_intern_cstr(mrb, "Status"))) {
+      c_status = mrb_class_get_under(mrb, c_process, "Status");
+    }
+  }
+  if (c_status != NULL) {
+    v = mrb_funcall(mrb, mrb_obj_value(c_status), "new", 2, mrb_fixnum_value(pid), mrb_fixnum_value(status));
+  } else {
+    v = mrb_fixnum_value(WEXITSTATUS(status));
+  }
+  mrb_gv_set(mrb, mrb_intern_cstr(mrb, "$?"), v);
+}
+#endif
+
+static int
+mrb_io_modestr_to_flags(mrb_state *mrb, const char *mode)
+{
+  int flags = 0;
+  const char *m = mode;
+
+  switch (*m++) {
+    case 'r':
+      flags |= FMODE_READABLE;
+      break;
+    case 'w':
+      flags |= FMODE_WRITABLE | FMODE_CREATE | FMODE_TRUNC;
+      break;
+    case 'a':
+      flags |= FMODE_WRITABLE | FMODE_APPEND | FMODE_CREATE;
+      break;
+    default:
+      mrb_raisef(mrb, E_ARGUMENT_ERROR, "illegal access mode %S", mrb_str_new_cstr(mrb, mode));
+  }
+
+  while (*m) {
+    switch (*m++) {
+      case 'b':
+        flags |= FMODE_BINMODE;
+        break;
+      case '+':
+        flags |= FMODE_READWRITE;
+        break;
+      case ':':
+        /* XXX: PASSTHROUGH*/
+      default:
+        mrb_raisef(mrb, E_ARGUMENT_ERROR, "illegal access mode %S", mrb_str_new_cstr(mrb, mode));
+    }
+  }
+
+  return flags;
+}
+
+static int
+mrb_io_flags_to_modenum(mrb_state *mrb, int flags)
+{
+  int modenum = 0;
+
+  switch(flags & (FMODE_READABLE|FMODE_WRITABLE|FMODE_READWRITE)) {
+    case FMODE_READABLE:
+      modenum = O_RDONLY;
+      break;
+    case FMODE_WRITABLE:
+      modenum = O_WRONLY;
+      break;
+    case FMODE_READWRITE:
+      modenum = O_RDWR;
+      break;
+  }
+
+  if (flags & FMODE_APPEND) {
+    modenum |= O_APPEND;
+  }
+  if (flags & FMODE_TRUNC) {
+    modenum |= O_TRUNC;
+  }
+  if (flags & FMODE_CREATE) {
+    modenum |= O_CREAT;
+  }
+#ifdef O_BINARY
+  if (flags & FMODE_BINMODE) {
+    modenum |= O_BINARY;
+  }
+#endif
+
+  return modenum;
+}
+
+void
+mrb_fd_cloexec(mrb_state *mrb, int fd)
+{
+#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
+  int flags, flags2;
+
+  flags = fcntl(fd, F_GETFD);
+  if (flags == -1) {
+    mrb_sys_fail(mrb, "fcntl");
+  }
+  if (fd <= 2) {
+    flags2 = flags & ~FD_CLOEXEC; /* Clear CLOEXEC for standard file descriptors: 0, 1, 2. */
+  }
+  else {
+    flags2 = flags | FD_CLOEXEC; /* Set CLOEXEC for non-standard file descriptors: 3, 4, 5, ... */
+  }
+  if (flags != flags2) {
+    if (fcntl(fd, F_SETFD, flags2) == -1) {
+      mrb_sys_fail(mrb, "fcntl");
+    }
+  }
+#endif
+}
+
+#ifndef _WIN32
+static int
+mrb_cloexec_pipe(mrb_state *mrb, int fildes[2])
+{
+  int ret;
+  ret = pipe(fildes);
+  if (ret == -1)
+    return -1;
+  mrb_fd_cloexec(mrb, fildes[0]);
+  mrb_fd_cloexec(mrb, fildes[1]);
+  return ret;
+}
+
+static int
+mrb_pipe(mrb_state *mrb, int pipes[2])
+{
+  int ret;
+  ret = mrb_cloexec_pipe(mrb, pipes);
+  if (ret == -1) {
+    if (errno == EMFILE || errno == ENFILE) {
+      mrb_garbage_collect(mrb);
+      ret = mrb_cloexec_pipe(mrb, pipes);
+    }
+  }
+  return ret;
+}
+
+static int
+mrb_proc_exec(const char *pname)
+{
+  const char *s;
+  s = pname;
+
+  while (*s == ' ' || *s == '\t' || *s == '\n')
+    s++;
+
+  if (!*s) {
+    errno = ENOENT;
+    return -1;
+  }
+
+  execl("/bin/sh", "sh", "-c", pname, (char *)NULL);
+  return -1;
+}
+#endif
+
+static void
+mrb_io_free(mrb_state *mrb, void *ptr)
+{
+  struct mrb_io *io = (struct mrb_io *)ptr;
+  if (io != NULL) {
+    fptr_finalize(mrb, io, TRUE);
+    mrb_free(mrb, io);
+  }
+}
+
+static struct mrb_io *
+mrb_io_alloc(mrb_state *mrb)
+{
+  struct mrb_io *fptr;
+
+  fptr = (struct mrb_io *)mrb_malloc(mrb, sizeof(struct mrb_io));
+  fptr->fd = -1;
+  fptr->fd2 = -1;
+  fptr->pid = 0;
+  fptr->readable = 0;
+  fptr->writable = 0;
+  fptr->sync = 0;
+  return fptr;
+}
+
+#ifndef NOFILE
+#define NOFILE 64
+#endif
+
+#ifndef _WIN32
+static int
+option_to_fd(mrb_state *mrb, mrb_value obj, const char *key)
+{
+  mrb_value opt = mrb_funcall(mrb, obj, "[]", 1, mrb_symbol_value(mrb_intern_static(mrb, key, strlen(key))));
+  if (mrb_nil_p(opt)) {
+    return -1;
+  }
+
+  switch (mrb_type(opt)) {
+    case MRB_TT_DATA: /* IO */
+      return mrb_fixnum(mrb_io_fileno(mrb, opt));
+    case MRB_TT_FIXNUM:
+      return mrb_fixnum(opt);
+    default:
+      mrb_raise(mrb, E_ARGUMENT_ERROR, "wrong exec redirect action");
+      break;
+  }
+  return -1; /* never reached */
+}
+
+mrb_value
+mrb_io_s_popen(mrb_state *mrb, mrb_value klass)
+{
+  mrb_value cmd, io, result;
+  mrb_value mode = mrb_str_new_cstr(mrb, "r");
+  mrb_value opt  = mrb_hash_new(mrb);
+
+  struct mrb_io *fptr;
+  const char *pname;
+  int pid, flags, fd, write_fd = -1;
+  int pr[2] = { -1, -1 };
+  int pw[2] = { -1, -1 };
+  int doexec;
+  int saved_errno;
+  int opt_in, opt_out, opt_err;
+
+  mrb_get_args(mrb, "S|SH", &cmd, &mode, &opt);
+  io = mrb_obj_value(mrb_data_object_alloc(mrb, mrb_class_ptr(klass), NULL, &mrb_io_type));
+
+  pname = mrb_string_value_cstr(mrb, &cmd);
+  flags = mrb_io_modestr_to_flags(mrb, mrb_string_value_cstr(mrb, &mode));
+
+  doexec = (strcmp("-", pname) != 0);
+  opt_in = option_to_fd(mrb, opt, "in");
+  opt_out = option_to_fd(mrb, opt, "out");
+  opt_err = option_to_fd(mrb, opt, "err");
+
+  if (flags & FMODE_READABLE) {
+    if (pipe(pr) == -1) {
+      mrb_sys_fail(mrb, "pipe");
+    }
+    mrb_fd_cloexec(mrb, pr[0]);
+    mrb_fd_cloexec(mrb, pr[1]);
+  }
+
+  if (flags & FMODE_WRITABLE) {
+    if (pipe(pw) == -1) {
+      if (pr[0] != -1) close(pr[0]);
+      if (pr[1] != -1) close(pr[1]);
+      mrb_sys_fail(mrb, "pipe");
+    }
+    mrb_fd_cloexec(mrb, pw[0]);
+    mrb_fd_cloexec(mrb, pw[1]);
+  }
+
+  if (!doexec) {
+    // XXX
+    fflush(stdin);
+    fflush(stdout);
+    fflush(stderr);
+  }
+
+  result = mrb_nil_value();
+  switch (pid = fork()) {
+    case 0: /* child */
+      if (opt_in != -1) {
+        dup2(opt_in, 0);
+      }
+      if (opt_out != -1) {
+        dup2(opt_out, 1);
+      }
+      if (opt_err != -1) {
+        dup2(opt_err, 2);
+      }
+      if (flags & FMODE_READABLE) {
+        close(pr[0]);
+        if (pr[1] != 1) {
+          dup2(pr[1], 1);
+          close(pr[1]);
+        }
+      }
+      if (flags & FMODE_WRITABLE) {
+        close(pw[1]);
+        if (pw[0] != 0) {
+          dup2(pw[0], 0);
+          close(pw[0]);
+        }
+      }
+      if (doexec) {
+        for (fd = 3; fd < NOFILE; fd++) {
+          close(fd);
+        }
+        mrb_proc_exec(pname);
+        mrb_raisef(mrb, E_IO_ERROR, "command not found: %S", cmd);
+        _exit(127);
+      }
+      result = mrb_nil_value();
+      break;
+
+    default: /* parent */
+      if ((flags & FMODE_READABLE) && (flags & FMODE_WRITABLE)) {
+        close(pr[1]);
+        fd = pr[0];
+        close(pw[0]);
+        write_fd = pw[1];
+      } else if (flags & FMODE_READABLE) {
+        close(pr[1]);
+        fd = pr[0];
+      } else {
+        close(pw[0]);
+        fd = pw[1];
+      }
+
+      mrb_iv_set(mrb, io, mrb_intern_cstr(mrb, "@buf"), mrb_str_new_cstr(mrb, ""));
+
+      fptr = mrb_io_alloc(mrb);
+      fptr->fd = fd;
+      fptr->fd2 = write_fd;
+      fptr->pid = pid;
+      fptr->readable = ((flags & FMODE_READABLE) != 0);
+      fptr->writable = ((flags & FMODE_WRITABLE) != 0);
+      fptr->sync = 0;
+
+      DATA_TYPE(io) = &mrb_io_type;
+      DATA_PTR(io)  = fptr;
+      result = io;
+      break;
+
+    case -1: /* error */
+      saved_errno = errno;
+      if (flags & FMODE_READABLE) {
+        close(pr[0]);
+        close(pr[1]);
+      }
+      if (flags & FMODE_WRITABLE) {
+        close(pw[0]);
+        close(pw[1]);
+      }
+      errno = saved_errno;
+      mrb_sys_fail(mrb, "pipe_open failed.");
+      break;
+  }
+  return result;
+}
+#endif
+
+mrb_value
+mrb_io_initialize(mrb_state *mrb, mrb_value io)
+{
+  struct mrb_io *fptr;
+  mrb_int fd;
+  mrb_value mode, opt;
+  int flags;
+
+  mode = opt = mrb_nil_value();
+
+  mrb_get_args(mrb, "i|So", &fd, &mode, &opt);
+  if (mrb_nil_p(mode)) {
+    mode = mrb_str_new_cstr(mrb, "r");
+  }
+  if (mrb_nil_p(opt)) {
+    opt = mrb_hash_new(mrb);
+  }
+
+  flags = mrb_io_modestr_to_flags(mrb, mrb_string_value_cstr(mrb, &mode));
+
+  mrb_iv_set(mrb, io, mrb_intern_cstr(mrb, "@buf"), mrb_str_new_cstr(mrb, ""));
+
+  fptr = (struct mrb_io *)DATA_PTR(io);
+  if (fptr != NULL) {
+    fptr_finalize(mrb, fptr, TRUE);
+    mrb_free(mrb, fptr);
+  }
+  fptr = mrb_io_alloc(mrb);
+
+  DATA_TYPE(io) = &mrb_io_type;
+  DATA_PTR(io) = fptr;
+
+  fptr->fd = fd;
+  fptr->readable = ((flags & FMODE_READABLE) != 0);
+  fptr->writable = ((flags & FMODE_WRITABLE) != 0);
+  fptr->sync = 0;
+  return io;
+}
+
+static void
+fptr_finalize(mrb_state *mrb, struct mrb_io *fptr, int quiet)
+{
+  int saved_errno = 0;
+
+  if (fptr == NULL) {
+    return;
+  }
+
+  if (fptr->fd > 2) {
+    if (close(fptr->fd) == -1) {
+      saved_errno = errno;
+    }
+    fptr->fd = -1;
+  }
+
+  if (fptr->fd2 > 2) {
+    if (close(fptr->fd2) == -1) {
+      if (saved_errno == 0) {
+        saved_errno = errno;
+      }
+    }
+    fptr->fd2 = -1;
+  }
+
+#if !defined(_WIN32) && !defined(_WIN64)
+  if (fptr->pid != 0) {
+    pid_t pid;
+    int status;
+    do {
+      pid = waitpid(fptr->pid, &status, 0);
+    } while (pid == -1 && errno == EINTR);
+    if (!quiet && pid == fptr->pid) {
+      io_set_process_status(mrb, pid, status);
+    }
+    fptr->pid = 0;
+    /* Note: we don't raise an exception when waitpid(3) fails */
+  }
+#endif
+
+  if (!quiet && saved_errno != 0) {
+    errno = saved_errno;
+    mrb_sys_fail(mrb, "fptr_finalize failed.");
+  }
+}
+
+mrb_value
+mrb_io_check_readable(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_io *fptr = io_get_open_fptr(mrb, self);
+  if (! fptr->readable) {
+    mrb_raise(mrb, E_IO_ERROR, "not opened for reading");
+  }
+  return mrb_nil_value();
+}
+
+mrb_value
+mrb_io_isatty(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_io *fptr;
+
+  fptr = io_get_open_fptr(mrb, self);
+  if (isatty(fptr->fd) == 0)
+    return mrb_false_value();
+  return mrb_true_value();
+}
+
+mrb_value
+mrb_io_s_for_fd(mrb_state *mrb, mrb_value klass)
+{
+  struct RClass *c = mrb_class_ptr(klass);
+  enum mrb_vtype ttype = MRB_INSTANCE_TT(c);
+  mrb_value obj;
+
+  /* copied from mrb_instance_alloc() */
+  if (ttype == 0) ttype = MRB_TT_OBJECT;
+  obj = mrb_obj_value((struct RObject*)mrb_obj_alloc(mrb, ttype, c));
+  return mrb_io_initialize(mrb, obj);
+}
+
+mrb_value
+mrb_io_s_sysclose(mrb_state *mrb, mrb_value klass)
+{
+  mrb_int fd;
+  mrb_get_args(mrb, "i", &fd);
+  if (close(fd) == -1) {
+    mrb_sys_fail(mrb, "close");
+  }
+  return mrb_fixnum_value(0);
+}
+
+int
+mrb_cloexec_open(mrb_state *mrb, const char *pathname, mrb_int flags, mrb_int mode)
+{
+  mrb_value emsg;
+  int fd, retry = FALSE;
+
+#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
+reopen:
+  fd = open(pathname, flags, mode);
+  if (fd == -1) {
+    if (!retry) {
+      switch (errno) {
+        case ENFILE:
+        case EMFILE:
+        mrb_garbage_collect(mrb);
+        retry = TRUE;
+        goto reopen;
+      }
+    }
+
+    emsg = mrb_format(mrb, "open %S", mrb_str_new_cstr(mrb, pathname));
+    mrb_str_modify(mrb, mrb_str_ptr(emsg));
+    mrb_sys_fail(mrb, RSTRING_PTR(emsg));
+  }
+
+  if (fd <= 2) {
+    mrb_fd_cloexec(mrb, fd);
+  }
+  return fd;
+}
+
+mrb_value
+mrb_io_s_sysopen(mrb_state *mrb, mrb_value klass)
+{
+  mrb_value path = mrb_nil_value();
+  mrb_value mode = mrb_nil_value();
+  mrb_int fd, flags, perm = -1;
+  const char *pat;
+  int modenum;
+
+  mrb_get_args(mrb, "S|Si", &path, &mode, &perm);
+  if (mrb_nil_p(mode)) {
+    mode = mrb_str_new_cstr(mrb, "r");
+  }
+  if (perm < 0) {
+    perm = 0666;
+  }
+
+  pat = mrb_string_value_cstr(mrb, &path);
+  flags = mrb_io_modestr_to_flags(mrb, mrb_string_value_cstr(mrb, &mode));
+  modenum = mrb_io_flags_to_modenum(mrb, flags);
+  fd = mrb_cloexec_open(mrb, pat, modenum, perm);
+  return mrb_fixnum_value(fd);
+}
+
+mrb_value
+mrb_io_sysread(mrb_state *mrb, mrb_value io)
+{
+  struct mrb_io *fptr;
+  mrb_value buf = mrb_nil_value();
+  mrb_int maxlen;
+  int ret;
+
+  mrb_get_args(mrb, "i|S", &maxlen, &buf);
+  if (maxlen < 0) {
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "negative expanding string size");
+  }
+  else if (maxlen == 0) {
+    return mrb_str_new(mrb, NULL, maxlen);
+  }
+
+  if (mrb_nil_p(buf)) {
+    buf = mrb_str_new(mrb, NULL, maxlen);
+  }
+
+  if (RSTRING_LEN(buf) != maxlen) {
+    buf = mrb_str_resize(mrb, buf, maxlen);
+  } else {
+    mrb_str_modify(mrb, RSTRING(buf));
+  }
+
+  fptr = (struct mrb_io *)io_get_open_fptr(mrb, io);
+  if (!fptr->readable) {
+    mrb_raise(mrb, E_IO_ERROR, "not opened for reading");
+  }
+  ret = read(fptr->fd, RSTRING_PTR(buf), maxlen);
+  switch (ret) {
+    case 0: /* EOF */
+      if (maxlen == 0) {
+        buf = mrb_str_new_cstr(mrb, "");
+      } else {
+        mrb_raise(mrb, E_EOF_ERROR, "sysread failed: End of File");
+      }
+      break;
+    case -1: /* Error */
+      mrb_sys_fail(mrb, "sysread failed");
+      break;
+    default:
+      if (RSTRING_LEN(buf) != ret) {
+        buf = mrb_str_resize(mrb, buf, ret);
+      }
+      break;
+  }
+
+  return buf;
+}
+
+mrb_value
+mrb_io_sysseek(mrb_state *mrb, mrb_value io)
+{
+  struct mrb_io *fptr;
+  off_t pos;
+  mrb_int offset, whence = -1;
+
+  mrb_get_args(mrb, "i|i", &offset, &whence);
+  if (whence < 0) {
+    whence = 0;
+  }
+
+  fptr = (struct mrb_io *)mrb_get_datatype(mrb, io, &mrb_io_type);
+  pos = lseek(fptr->fd, offset, whence);
+  if (pos == -1) {
+    mrb_sys_fail(mrb, "sysseek");
+  }
+  if (pos > MRB_INT_MAX) {
+    return mrb_float_value(mrb, (mrb_float)pos);
+  } else {
+    return mrb_fixnum_value(pos);
+  }
+}
+
+mrb_value
+mrb_io_syswrite(mrb_state *mrb, mrb_value io)
+{
+  struct mrb_io *fptr;
+  mrb_value str, buf;
+  int fd, length;
+
+  fptr = (struct mrb_io *)mrb_get_datatype(mrb, io, &mrb_io_type);
+  if (! fptr->writable) {
+    mrb_raise(mrb, E_IO_ERROR, "not opened for writing");
+  }
+
+  mrb_get_args(mrb, "S", &str);
+  if (mrb_type(str) != MRB_TT_STRING) {
+    buf = mrb_funcall(mrb, str, "to_s", 0);
+  } else {
+    buf = str;
+  }
+
+  if (fptr->fd2 == -1) {
+    fd = fptr->fd;
+  } else {
+    fd = fptr->fd2;
+  }
+  length = write(fd, RSTRING_PTR(buf), RSTRING_LEN(buf));
+  if (length == -1) {
+    mrb_sys_fail(mrb, 0);
+  }
+
+  return mrb_fixnum_value(length);
+}
+
+mrb_value
+mrb_io_close(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_io *fptr;
+  fptr = io_get_open_fptr(mrb, self);
+  fptr_finalize(mrb, fptr, FALSE);
+  return mrb_nil_value();
+}
+
+mrb_value
+mrb_io_closed(mrb_state *mrb, mrb_value io)
+{
+  struct mrb_io *fptr;
+  fptr = (struct mrb_io *)mrb_get_datatype(mrb, io, &mrb_io_type);
+  if (fptr->fd >= 0) {
+    return mrb_false_value();
+  }
+
+  return mrb_true_value();
+}
+
+mrb_value
+mrb_io_pid(mrb_state *mrb, mrb_value io)
+{
+  struct mrb_io *fptr;
+  fptr = (struct mrb_io *)mrb_get_datatype(mrb, io, &mrb_io_type);
+
+  if (fptr->pid > 0) {
+    return mrb_fixnum_value(fptr->pid);
+  }
+
+  return mrb_nil_value();
+}
+
+static struct timeval
+time2timeval(mrb_state *mrb, mrb_value time)
+{
+  struct timeval t = { 0, 0 };
+
+  switch (mrb_type(time)) {
+    case MRB_TT_FIXNUM:
+      t.tv_sec = mrb_fixnum(time);
+      t.tv_usec = 0;
+      break;
+
+    case MRB_TT_FLOAT:
+      t.tv_sec = mrb_float(time);
+      t.tv_usec = (mrb_float(time) - t.tv_sec) * 1000000.0;
+      break;
+
+    default:
+      mrb_raise(mrb, E_TYPE_ERROR, "wrong argument class");
+  }
+
+  return t;
+}
+
+static int
+mrb_io_read_data_pending(mrb_state *mrb, mrb_value io)
+{
+  mrb_value buf = mrb_iv_get(mrb, io, mrb_intern_cstr(mrb, "@buf"));
+  if (mrb_type(buf) == MRB_TT_STRING && RSTRING_LEN(buf) > 0) {
+    return 1;
+  }
+  return 0;
+}
+
+#ifndef _WIN32
+static mrb_value
+mrb_io_s_pipe(mrb_state *mrb, mrb_value klass)
+{
+  mrb_value r = mrb_nil_value();
+  mrb_value w = mrb_nil_value();
+  struct mrb_io *fptr_r;
+  struct mrb_io *fptr_w;
+  int pipes[2];
+
+  if (mrb_pipe(mrb, pipes) == -1) {
+    mrb_sys_fail(mrb, "pipe");
+  }
+
+  r = mrb_obj_value(mrb_data_object_alloc(mrb, mrb_class_ptr(klass), NULL, &mrb_io_type));
+  mrb_iv_set(mrb, r, mrb_intern_cstr(mrb, "@buf"), mrb_str_new_cstr(mrb, ""));
+  fptr_r = mrb_io_alloc(mrb);
+  fptr_r->fd = pipes[0];
+  fptr_r->readable = 1;
+  fptr_r->writable = 0;
+  fptr_r->sync = 0;
+  DATA_TYPE(r) = &mrb_io_type;
+  DATA_PTR(r)  = fptr_r;
+
+  w = mrb_obj_value(mrb_data_object_alloc(mrb, mrb_class_ptr(klass), NULL, &mrb_io_type));
+  mrb_iv_set(mrb, w, mrb_intern_cstr(mrb, "@buf"), mrb_str_new_cstr(mrb, ""));
+  fptr_w = mrb_io_alloc(mrb);
+  fptr_w->fd = pipes[1];
+  fptr_w->readable = 0;
+  fptr_w->writable = 1;
+  fptr_w->sync = 1;
+  DATA_TYPE(w) = &mrb_io_type;
+  DATA_PTR(w)  = fptr_w;
+
+  return mrb_assoc_new(mrb, r, w);
+}
+#endif
+
+static mrb_value
+mrb_io_s_select(mrb_state *mrb, mrb_value klass)
+{
+  mrb_value *argv;
+  mrb_int argc;
+  mrb_value read, read_io, write, except, timeout, list;
+  struct timeval *tp, timerec;
+  fd_set pset, rset, wset, eset;
+  fd_set *rp, *wp, *ep;
+  struct mrb_io *fptr;
+  int pending = 0;
+  mrb_value result;
+  int max = 0;
+  int interrupt_flag = 0;
+  int i, n;
+
+  mrb_get_args(mrb, "*", &argv, &argc);
+
+  if (argc < 1 || argc > 4) {
+    mrb_raisef(mrb, E_ARGUMENT_ERROR, "wrong number of arguments (%S for 1..4)", mrb_fixnum_value(argc));
+  }
+
+  timeout = mrb_nil_value();
+  except = mrb_nil_value();
+  write = mrb_nil_value();
+  if (argc > 3)
+    timeout = argv[3];
+  if (argc > 2)
+    except = argv[2];
+  if (argc > 1)
+    write = argv[1];
+  read = argv[0];
+
+  if (mrb_nil_p(timeout)) {
+    tp = NULL;
+  } else {
+    timerec = time2timeval(mrb, timeout);
+    tp = &timerec;
+  }
+
+  FD_ZERO(&pset);
+  if (!mrb_nil_p(read)) {
+    mrb_check_type(mrb, read, MRB_TT_ARRAY);
+    rp = &rset;
+    FD_ZERO(rp);
+    for (i = 0; i < RARRAY_LEN(read); i++) {
+      read_io = RARRAY_PTR(read)[i];
+      fptr = (struct mrb_io *)mrb_get_datatype(mrb, read_io, &mrb_io_type);
+      FD_SET(fptr->fd, rp);
+      if (mrb_io_read_data_pending(mrb, read_io)) {
+        pending++;
+        FD_SET(fptr->fd, &pset);
+      }
+      if (max < fptr->fd)
+        max = fptr->fd;
+    }
+    if (pending) {
+      timerec.tv_sec = timerec.tv_usec = 0;
+      tp = &timerec;
+    }
+  } else {
+    rp = NULL;
+  }
+
+  if (!mrb_nil_p(write)) {
+    mrb_check_type(mrb, write, MRB_TT_ARRAY);
+    wp = &wset;
+    FD_ZERO(wp);
+    for (i = 0; i < RARRAY_LEN(write); i++) {
+      fptr = (struct mrb_io *)mrb_get_datatype(mrb, RARRAY_PTR(write)[i], &mrb_io_type);
+      FD_SET(fptr->fd, wp);
+      if (max < fptr->fd)
+        max = fptr->fd;
+      if (fptr->fd2 >= 0) {
+        FD_SET(fptr->fd2, wp);
+        if (max < fptr->fd2)
+          max = fptr->fd2;
+      }
+    }
+  } else {
+    wp = NULL;
+  }
+
+  if (!mrb_nil_p(except)) {
+    mrb_check_type(mrb, except, MRB_TT_ARRAY);
+    ep = &eset;
+    FD_ZERO(ep);
+    for (i = 0; i < RARRAY_LEN(except); i++) {
+      fptr = (struct mrb_io *)mrb_get_datatype(mrb, RARRAY_PTR(except)[i], &mrb_io_type);
+      FD_SET(fptr->fd, ep);
+      if (max < fptr->fd)
+        max = fptr->fd;
+      if (fptr->fd2 >= 0) {
+        FD_SET(fptr->fd2, ep);
+        if (max < fptr->fd2)
+          max = fptr->fd2;
+      }
+    }
+  } else {
+    ep = NULL;
+  }
+
+  max++;
+
+retry:
+  n = select(max, rp, wp, ep, tp);
+  if (n < 0) {
+    if (errno != EINTR)
+      mrb_sys_fail(mrb, "select failed");
+    if (tp == NULL)
+      goto retry;
+    interrupt_flag = 1;
+  }
+
+  if (!pending && n == 0)
+    return mrb_nil_value();
+
+  result = mrb_ary_new_capa(mrb, 3);
+  mrb_ary_push(mrb, result, rp? mrb_ary_new(mrb) : mrb_ary_new_capa(mrb, 0));
+  mrb_ary_push(mrb, result, wp? mrb_ary_new(mrb) : mrb_ary_new_capa(mrb, 0));
+  mrb_ary_push(mrb, result, ep? mrb_ary_new(mrb) : mrb_ary_new_capa(mrb, 0));
+
+  if (interrupt_flag == 0) {
+    if (rp) {
+      list = RARRAY_PTR(result)[0];
+      for (i = 0; i < RARRAY_LEN(read); i++) {
+        fptr = (struct mrb_io *)mrb_get_datatype(mrb, RARRAY_PTR(read)[i], &mrb_io_type);
+        if (FD_ISSET(fptr->fd, rp) ||
+            FD_ISSET(fptr->fd, &pset)) {
+          mrb_ary_push(mrb, list, RARRAY_PTR(read)[i]);
+        }
+      }
+    }
+
+    if (wp) {
+      list = RARRAY_PTR(result)[1];
+      for (i = 0; i < RARRAY_LEN(write); i++) {
+        fptr = (struct mrb_io *)mrb_get_datatype(mrb, RARRAY_PTR(write)[i], &mrb_io_type);
+        if (FD_ISSET(fptr->fd, wp)) {
+          mrb_ary_push(mrb, list, RARRAY_PTR(write)[i]);
+        } else if (fptr->fd2 >= 0 && FD_ISSET(fptr->fd2, wp)) {
+          mrb_ary_push(mrb, list, RARRAY_PTR(write)[i]);
+        }
+      }
+    }
+
+    if (ep) {
+      list = RARRAY_PTR(result)[2];
+      for (i = 0; i < RARRAY_LEN(except); i++) {
+        fptr = (struct mrb_io *)mrb_get_datatype(mrb, RARRAY_PTR(except)[i], &mrb_io_type);
+        if (FD_ISSET(fptr->fd, ep)) {
+          mrb_ary_push(mrb, list, RARRAY_PTR(except)[i]);
+        } else if (fptr->fd2 >= 0 && FD_ISSET(fptr->fd2, ep)) {
+          mrb_ary_push(mrb, list, RARRAY_PTR(except)[i]);
+        }
+      }
+    }
+  }
+
+  return result;
+}
+
+mrb_value
+mrb_io_fileno(mrb_state *mrb, mrb_value io)
+{
+  struct mrb_io *fptr;
+  fptr = (struct mrb_io *)mrb_get_datatype(mrb, io, &mrb_io_type);
+  return mrb_fixnum_value(fptr->fd);
+}
+
+mrb_value
+mrb_io_close_on_exec_p(mrb_state *mrb, mrb_value self)
+{
+#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
+  struct mrb_io *fptr;
+  int ret;
+
+  fptr = io_get_open_fptr(mrb, self);
+
+  if (fptr->fd2 >= 0) {
+    if ((ret = fcntl(fptr->fd2, F_GETFD)) == -1) mrb_sys_fail(mrb, "F_GETFD failed");
+    if (!(ret & FD_CLOEXEC)) return mrb_false_value();
+  }
+
+  if ((ret = fcntl(fptr->fd, F_GETFD)) == -1) mrb_sys_fail(mrb, "F_GETFD failed");
+  if (!(ret & FD_CLOEXEC)) return mrb_false_value();
+  return mrb_true_value();
+
+#else
+  mrb_raise(mrb, E_NOTIMP_ERROR, "IO#close_on_exec? is not supported on the platform");
+  return mrb_false_value();
+#endif
+}
+
+mrb_value
+mrb_io_set_close_on_exec(mrb_state *mrb, mrb_value self)
+{
+#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
+  struct mrb_io *fptr;
+  int flag, ret;
+  mrb_bool b;
+
+  fptr = io_get_open_fptr(mrb, self);
+  mrb_get_args(mrb, "b", &b);
+  flag = b ? FD_CLOEXEC : 0;
+
+  if (fptr->fd2 >= 0) {
+    if ((ret = fcntl(fptr->fd2, F_GETFD)) == -1) mrb_sys_fail(mrb, "F_GETFD failed");
+    if ((ret & FD_CLOEXEC) != flag) {
+      ret = (ret & ~FD_CLOEXEC) | flag;
+      ret = fcntl(fptr->fd2, F_SETFD, ret);
+
+      if (ret == -1) mrb_sys_fail(mrb, "F_SETFD failed");
+    }
+  }
+
+  if ((ret = fcntl(fptr->fd, F_GETFD)) == -1) mrb_sys_fail(mrb, "F_GETFD failed");
+  if ((ret & FD_CLOEXEC) != flag) {
+    ret = (ret & ~FD_CLOEXEC) | flag;
+    ret = fcntl(fptr->fd, F_SETFD, ret);
+    if (ret == -1) mrb_sys_fail(mrb, "F_SETFD failed");
+  }
+
+  return mrb_bool_value(b);
+#else
+  mrb_raise(mrb, E_NOTIMP_ERROR, "IO#close_on_exec= is not supported on the platform");
+  return mrb_nil_value();
+#endif
+}
+
+mrb_value
+mrb_io_set_sync(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_io *fptr;
+  mrb_bool b;
+
+  fptr = io_get_open_fptr(mrb, self);
+  mrb_get_args(mrb, "b", &b);
+  fptr->sync = b;
+  return mrb_bool_value(b);
+}
+
+mrb_value
+mrb_io_sync(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_io *fptr;
+  fptr = io_get_open_fptr(mrb, self);
+  return mrb_bool_value(fptr->sync);
+}
+
+void
+mrb_init_io(mrb_state *mrb)
+{
+  struct RClass *io;
+
+  io      = mrb_define_class(mrb, "IO", mrb->object_class);
+  MRB_SET_INSTANCE_TT(io, MRB_TT_DATA);
+
+  mrb_include_module(mrb, io, mrb_module_get(mrb, "Enumerable")); /* 15.2.20.3 */
+#ifndef _WIN32
+  mrb_define_class_method(mrb, io, "_popen",  mrb_io_s_popen,   MRB_ARGS_ANY());
+  mrb_define_class_method(mrb, io, "_sysclose",  mrb_io_s_sysclose, MRB_ARGS_REQ(1));
+#endif
+  mrb_define_class_method(mrb, io, "for_fd",  mrb_io_s_for_fd,   MRB_ARGS_ANY());
+  mrb_define_class_method(mrb, io, "select",  mrb_io_s_select,  MRB_ARGS_ANY());
+  mrb_define_class_method(mrb, io, "sysopen", mrb_io_s_sysopen, MRB_ARGS_ANY());
+#ifndef _WIN32
+  mrb_define_class_method(mrb, io, "_pipe", mrb_io_s_pipe, MRB_ARGS_NONE());
+#endif
+
+  mrb_define_method(mrb, io, "initialize", mrb_io_initialize, MRB_ARGS_ANY());    /* 15.2.20.5.21 (x)*/
+  mrb_define_method(mrb, io, "_check_readable", mrb_io_check_readable, MRB_ARGS_NONE());
+  mrb_define_method(mrb, io, "isatty",     mrb_io_isatty,     MRB_ARGS_NONE());
+  mrb_define_method(mrb, io, "sync",       mrb_io_sync,       MRB_ARGS_NONE());
+  mrb_define_method(mrb, io, "sync=",      mrb_io_set_sync,   MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, io, "sysread",    mrb_io_sysread,    MRB_ARGS_ANY());
+  mrb_define_method(mrb, io, "sysseek",    mrb_io_sysseek,    MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, io, "syswrite",   mrb_io_syswrite,   MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, io, "close",      mrb_io_close,      MRB_ARGS_NONE());   /* 15.2.20.5.1 */
+  mrb_define_method(mrb, io, "close_on_exec=", mrb_io_set_close_on_exec, MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, io, "close_on_exec?", mrb_io_close_on_exec_p,   MRB_ARGS_NONE());
+  mrb_define_method(mrb, io, "closed?",    mrb_io_closed,     MRB_ARGS_NONE());   /* 15.2.20.5.2 */
+  mrb_define_method(mrb, io, "pid",        mrb_io_pid,        MRB_ARGS_NONE());   /* 15.2.20.5.2 */
+  mrb_define_method(mrb, io, "fileno",     mrb_io_fileno,     MRB_ARGS_NONE());
+
+
+  mrb_gv_set(mrb, mrb_intern_cstr(mrb, "$/"), mrb_str_new_cstr(mrb, "\n"));
+}