/* Open a descriptor to a file.
- Copyright (C) 2007-2011 Free Software Foundation, Inc.
+ Copyright (C) 2007-2021 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
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/>. */
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
+/* If the user's config.h happens to include <fcntl.h>, let it include only
+ the system's <fcntl.h> here, so that orig_open doesn't recurse to
+ rpl_open. */
+#define __need_system_fcntl_h
#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>
+#undef __need_system_fcntl_h
-static inline int
+static int
orig_open (const char *filename, int flags, mode_t mode)
{
+#if defined _WIN32 && !defined __CYGWIN__
+ return _open (filename, flags, mode);
+#else
return open (filename, flags, mode);
+#endif
}
/* Specification. */
-#include <fcntl.h>
+/* Write "fcntl.h" here, not <fcntl.h>, otherwise OSF/1 5.1 DTK cc eliminates
+ this include because of the preliminary #include <fcntl.h> above. */
+#include "fcntl.h"
+
+#include "cloexec.h"
#include <errno.h>
#include <stdarg.h>
int
open (const char *filename, int flags, ...)
{
+ /* 0 = unknown, 1 = yes, -1 = no. */
+#if GNULIB_defined_O_CLOEXEC
+ int have_cloexec = -1;
+#else
+ static int have_cloexec;
+#endif
+
mode_t mode;
int fd;
va_end (arg);
}
-#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+#if GNULIB_defined_O_NONBLOCK
+ /* The only known platform that lacks O_NONBLOCK is mingw, but it
+ also lacks named pipes and Unix sockets, which are the only two
+ file types that require non-blocking handling in open().
+ Therefore, it is safe to ignore O_NONBLOCK here. It is handy
+ that mingw also lacks openat(), so that is also covered here. */
+ flags &= ~O_NONBLOCK;
+#endif
+
+#if 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."
+ /* Fail if one of O_CREAT, O_WRONLY, O_RDWR is specified and the filename
+ ends in a slash, as POSIX says such a filename must name a directory
+ <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
+ "A pathname that contains at least one non-<slash> character and that
+ ends with one or more trailing <slash> characters shall not be resolved
+ successfully unless the last pathname component before the trailing
+ <slash> characters names an existing directory"
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.
+ <https://pubs.opengroup.org/onlinepubs/9699919799/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))
+ if ((flags & O_CREAT)
+ || (flags & O_ACCMODE) == O_RDWR
+ || (flags & O_ACCMODE) == O_WRONLY)
{
size_t len = strlen (filename);
if (len > 0 && filename[len - 1] == '/')
}
#endif
- fd = orig_open (filename, flags, mode);
+ fd = orig_open (filename,
+ flags & ~(have_cloexec < 0 ? O_CLOEXEC : 0), mode);
+
+ if (flags & O_CLOEXEC)
+ {
+ if (! have_cloexec)
+ {
+ if (0 <= fd)
+ have_cloexec = 1;
+ else if (errno == EINVAL)
+ {
+ fd = orig_open (filename, flags & ~O_CLOEXEC, mode);
+ have_cloexec = -1;
+ }
+ }
+ if (have_cloexec < 0 && 0 <= fd)
+ set_cloexec_flag (fd, true);
+ }
+
#if REPLACE_FCHDIR
/* Implementing fchdir and fdopendir requires the ability to open a
#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."
+ Rationale: POSIX says such a filename must name a directory
+ <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
+ "A pathname that contains at least one non-<slash> character and that
+ ends with one or more trailing <slash> characters shall not be resolved
+ successfully unless the last pathname component before the trailing
+ <slash> characters names an existing directory"
If the named file without the slash is not a directory, open() must fail
with ENOTDIR. */
if (fd >= 0)