blob: 3408192570be213a5571e397ff97bec2d67cc8c0 [file] [log] [blame]
/* Open a stream to a file.
Copyright (C) 2007-2012 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
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 <>. */
/* Written by Bruno Haible <>, 2007. */
/* If the user's config.h happens to include <stdio.h>, let it include only
the system's <stdio.h> here, so that orig_fopen doesn't recurse to
rpl_fopen. */
#define __need_FILE
#include <config.h>
/* Get the original definition of fopen. It might be defined as a macro. */
#include <stdio.h>
#undef __need_FILE
static FILE *
orig_fopen (const char *filename, const char *mode)
return fopen (filename, mode);
/* Specification. */
/* Write "stdio.h" here, not <stdio.h>, otherwise OSF/1 5.1 DTK cc eliminates
this include because of the preliminary #include <stdio.h> above. */
#include "stdio.h"
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
rpl_fopen (const char *filename, const char *mode)
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
if (strcmp (filename, "/dev/null") == 0)
filename = "NUL";
/* If the filename ends in a slash and a mode that requires write access is
specified, then fail.
Rationale: POSIX <>
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."
"The special filename dot shall refer to the directory specified by
its predecessor."
If the named file already exists as a directory, then if a mode that
requires write access is specified, fopen() must fail because POSIX
<> says that it
fails with errno = EISDIR in this case.
If the named file does not exist or does not name a directory, then
fopen() must fail since the file does not contain a '.' directory. */
size_t len = strlen (filename);
if (len > 0 && filename[len - 1] == '/')
int fd;
struct stat statbuf;
FILE *fp;
if (mode[0] == 'w' || mode[0] == 'a')
errno = EISDIR;
return NULL;
fd = open (filename, O_RDONLY);
if (fd < 0)
return NULL;
if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
close (fd);
errno = ENOTDIR;
return NULL;
fp = fdopen (fd, mode);
if (fp == NULL)
int saved_errno = errno;
close (fd);
errno = saved_errno;
return fp;
# endif
return orig_fopen (filename, mode);