| /* Open a stream to a file. |
| Copyright (C) 2007-2019 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 <https://www.gnu.org/licenses/>. */ |
| |
| /* Written by Bruno Haible <bruno@clisp.org>, 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> |
| |
| FILE * |
| rpl_fopen (const char *filename, const char *mode) |
| { |
| #if defined _WIN32 && ! defined __CYGWIN__ |
| if (strcmp (filename, "/dev/null") == 0) |
| filename = "NUL"; |
| #endif |
| |
| #if FOPEN_TRAILING_SLASH_BUG |
| /* Fail if the mode requires write access 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 a mode that |
| requires write access is specified, fopen() must fail because POSIX |
| <https://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.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 |
| 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); |
| } |