1 /* Open a descriptor to a file.
2 Copyright (C) 2007-2008 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Written by Bruno Haible <bruno@clisp.org>, 2007. */
21 /* Get the original definition of open. It might be defined as a macro. */
22 #define __need_system_fcntl_h
24 #undef __need_system_fcntl_h
25 #include <sys/types.h>
28 orig_open (const char *filename, int flags, mode_t mode)
30 return open (filename, flags, mode);
39 #include <sys/types.h>
43 open (const char *filename, int flags, ...)
52 va_start (arg, flags);
54 /* If mode_t is narrower than int, use the promoted type (int),
55 not mode_t. Use sizeof to guess whether mode_t is narrower;
56 we don't know of any practical counterexamples. */
57 mode = (sizeof (mode_t) < sizeof (int)
59 : va_arg (arg, mode_t));
64 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
65 if (strcmp (filename, "/dev/null") == 0)
69 #if OPEN_TRAILING_SLASH_BUG
70 /* If the filename ends in a slash and one of O_CREAT, O_WRONLY, O_RDWR
71 is specified, then fail.
72 Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
74 "A pathname that contains at least one non-slash character and that
75 ends with one or more trailing slashes shall be resolved as if a
76 single dot character ( '.' ) were appended to the pathname."
78 "The special filename dot shall refer to the directory specified by
80 If the named file already exists as a directory, then
81 - if O_CREAT is specified, open() must fail because of the semantics
83 - if O_WRONLY or O_RDWR is specified, open() must fail because POSIX
84 <http://www.opengroup.org/susv3/functions/open.html> says that it
85 fails with errno = EISDIR in this case.
86 If the named file does not exist or does not name a directory, then
87 - if O_CREAT is specified, open() must fail since open() cannot create
89 - if O_WRONLY or O_RDWR is specified, open() must fail because the
90 file does not contain a '.' directory. */
91 if (flags & (O_CREAT | O_WRONLY | O_RDWR))
93 size_t len = strlen (filename);
94 if (len > 0 && filename[len - 1] == '/')
102 fd = orig_open (filename, flags, mode);
104 #if OPEN_TRAILING_SLASH_BUG
105 /* If the filename ends in a slash and fd does not refer to a directory,
107 Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
109 "A pathname that contains at least one non-slash character and that
110 ends with one or more trailing slashes shall be resolved as if a
111 single dot character ( '.' ) were appended to the pathname."
113 "The special filename dot shall refer to the directory specified by
115 If the named file without the slash is not a directory, open() must fail
119 size_t len = strlen (filename);
120 if (len > 0 && filename[len - 1] == '/')
124 if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
134 #ifdef FCHDIR_REPLACEMENT
136 _gl_register_fd (fd, filename);