108 lines
3.4 KiB
C
108 lines
3.4 KiB
C
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/* Open a stream to a file.
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Copyright (C) 2007-2020 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
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/* If the user's config.h happens to include <stdio.h>, let it include only
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the system's <stdio.h> here, so that orig_fopen doesn't recurse to
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rpl_fopen. */
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#define __need_FILE
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#include <config.h>
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/* Get the original definition of fopen. It might be defined as a macro. */
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#include <stdio.h>
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#undef __need_FILE
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static FILE *
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orig_fopen (const char *filename, const char *mode)
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{
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return fopen (filename, mode);
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}
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/* Specification. */
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/* Write "stdio.h" here, not <stdio.h>, otherwise OSF/1 5.1 DTK cc eliminates
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this include because of the preliminary #include <stdio.h> above. */
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#include "stdio.h"
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#include <errno.h>
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#include <fcntl.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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FILE *
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rpl_fopen (const char *filename, const char *mode)
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{
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#if defined _WIN32 && ! defined __CYGWIN__
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if (strcmp (filename, "/dev/null") == 0)
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filename = "NUL";
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#endif
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#if FOPEN_TRAILING_SLASH_BUG
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/* Fail if the mode requires write access and the filename ends in a slash,
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as POSIX says such a filename must name a directory
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<https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
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"A pathname that contains at least one non-<slash> character and that
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ends with one or more trailing <slash> characters shall not be resolved
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successfully unless the last pathname component before the trailing
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<slash> characters names an existing directory"
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If the named file already exists as a directory, then if a mode that
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requires write access is specified, fopen() must fail because POSIX
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<https://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html>
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says that it fails with errno = EISDIR in this case.
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If the named file does not exist or does not name a directory, then
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fopen() must fail since the file does not contain a '.' directory. */
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{
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size_t len = strlen (filename);
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if (len > 0 && filename[len - 1] == '/')
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{
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int fd;
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struct stat statbuf;
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FILE *fp;
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if (mode[0] == 'w' || mode[0] == 'a')
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{
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errno = EISDIR;
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return NULL;
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}
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fd = open (filename, O_RDONLY);
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if (fd < 0)
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return NULL;
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if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
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{
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close (fd);
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errno = ENOTDIR;
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return NULL;
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}
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fp = fdopen (fd, mode);
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if (fp == NULL)
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{
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int saved_errno = errno;
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close (fd);
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errno = saved_errno;
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}
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return fp;
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}
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}
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# endif
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return orig_fopen (filename, mode);
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}
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