+
−/* Open a descriptor to a file.
+
−   Copyright (C) 2007-2010 Free Software Foundation, Inc.
+
−
+
−   This program is free software: you can redistribute it and/or modify
+
−   it under the terms of the GNU General Public License as published by
+
−   the Free Software Foundation; either version 3 of the License, or
+
−   (at your option) any later version.
+
−
+
−   This program is distributed in the hope that it will be useful,
+
−   but WITHOUT ANY WARRANTY; without even the implied warranty of
+
−   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+
−   GNU General Public License for more details.
+
−
+
−   You should have received a copy of the GNU General Public License
+
−   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
−
+
−/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
+
−
+
−#include <config.h>
+
−
+
−/* Get the original definition of open.  It might be defined as a macro.  */
+
−#define __need_system_fcntl_h
+
−#include <fcntl.h>
+
−#undef __need_system_fcntl_h
+
−#include <sys/types.h>
+
−
+
−static inline int
+
−orig_open (const char *filename, int flags, mode_t mode)
+
−{
+
−  return open (filename, flags, mode);
+
−}
+
−
+
−/* Specification.  */
+
−#include <fcntl.h>
+
−
+
−#include <errno.h>
+
−#include <stdarg.h>
+
−#include <string.h>
+
−#include <sys/types.h>
+
−#include <sys/stat.h>
+
−#include <unistd.h>
+
−
+
−#ifndef REPLACE_OPEN_DIRECTORY
+
−# define REPLACE_OPEN_DIRECTORY 0
+
−#endif
+
−
+
−int
+
−open (const char *filename, int flags, ...)
+
−{
+
−  mode_t mode;
+
−  int fd;
+
−
+
−  mode = 0;
+
−  if (flags & O_CREAT)
+
−    {
+
−      va_list arg;
+
−      va_start (arg, flags);
+
−
+
−      /* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4
+
−         creates crashing code when 'mode_t' is smaller than 'int'.  */
+
−      mode = va_arg (arg, PROMOTED_MODE_T);
+
−
+
−      va_end (arg);
+
−    }
+
−
+
−#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
−  if (strcmp (filename, "/dev/null") == 0)
+
−    filename = "NUL";
+
−#endif
+
−
+
−#if OPEN_TRAILING_SLASH_BUG
+
−  /* If the filename ends in a slash and one of O_CREAT, O_WRONLY, O_RDWR
+
−     is specified, then fail.
+
−     Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
+
−     says that
+
−       "A pathname that contains at least one non-slash character and that
+
−        ends with one or more trailing slashes shall be resolved as if a
+
−        single dot character ( '.' ) were appended to the pathname."
+
−     and
+
−       "The special filename dot shall refer to the directory specified by
+
−        its predecessor."
+
−     If the named file already exists as a directory, then
+
−       - if O_CREAT is specified, open() must fail because of the semantics
+
−         of O_CREAT,
+
−       - if O_WRONLY or O_RDWR is specified, open() must fail because POSIX
+
−         <http://www.opengroup.org/susv3/functions/open.html> says that it
+
−         fails with errno = EISDIR in this case.
+
−     If the named file does not exist or does not name a directory, then
+
−       - if O_CREAT is specified, open() must fail since open() cannot create
+
−         directories,
+
−       - if O_WRONLY or O_RDWR is specified, open() must fail because the
+
−         file does not contain a '.' directory.  */
+
−  if (flags & (O_CREAT | O_WRONLY | O_RDWR))
+
−    {
+
−      size_t len = strlen (filename);
+
−      if (len > 0 && filename[len - 1] == '/')
+
−        {
+
−          errno = EISDIR;
+
−          return -1;
+
−        }
+
−    }
+
−#endif
+
−
+
−  fd = orig_open (filename, flags, mode);
+
−
+
−#if REPLACE_FCHDIR
+
−  /* Implementing fchdir and fdopendir requires the ability to open a
+
−     directory file descriptor.  If open doesn't support that (as on
+
−     mingw), we use a dummy file that behaves the same as directories
+
−     on Linux (ie. always reports EOF on attempts to read()), and
+
−     override fstat() in fchdir.c to hide the fact that we have a
+
−     dummy.  */
+
−  if (REPLACE_OPEN_DIRECTORY && fd < 0 && errno == EACCES
+
−      && (flags & O_ACCMODE) == O_RDONLY)
+
−    {
+
−      struct stat statbuf;
+
−      if (stat (filename, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
+
−        {
+
−          /* Maximum recursion depth of 1.  */
+
−          fd = open ("/dev/null", flags, mode);
+
−          if (0 <= fd)
+
−            fd = _gl_register_fd (fd, filename);
+
−        }
+
−      else
+
−        errno = EACCES;
+
−    }
+
−#endif
+
−
+
−#if OPEN_TRAILING_SLASH_BUG
+
−  /* If the filename ends in a slash and fd does not refer to a directory,
+
−     then fail.
+
−     Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
+
−     says that
+
−       "A pathname that contains at least one non-slash character and that
+
−        ends with one or more trailing slashes shall be resolved as if a
+
−        single dot character ( '.' ) were appended to the pathname."
+
−     and
+
−       "The special filename dot shall refer to the directory specified by
+
−        its predecessor."
+
−     If the named file without the slash is not a directory, open() must fail
+
−     with ENOTDIR.  */
+
−  if (fd >= 0)
+
−    {
+
−      /* We know len is positive, since open did not fail with ENOENT.  */
+
−      size_t len = strlen (filename);
+
−      if (filename[len - 1] == '/')
+
−        {
+
−          struct stat statbuf;
+
−
+
−          if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
+
−            {
+
−              close (fd);
+
−              errno = ENOTDIR;
+
−              return -1;
+
−            }
+
−        }
+
−    }
+
−#endif
+
−
+
−#if REPLACE_FCHDIR
+
−  if (!REPLACE_OPEN_DIRECTORY && 0 <= fd)
+
−    fd = _gl_register_fd (fd, filename);
+
−#endif
+
−
+
−  return fd;
+
−}