105436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Open a stream to a file. 205436638acc7c010349a69c3395f1a57c642dc62Ying Wang Copyright (C) 2007-2012 Free Software Foundation, Inc. 305436638acc7c010349a69c3395f1a57c642dc62Ying Wang 405436638acc7c010349a69c3395f1a57c642dc62Ying Wang This program is free software: you can redistribute it and/or modify 505436638acc7c010349a69c3395f1a57c642dc62Ying Wang it under the terms of the GNU General Public License as published by 605436638acc7c010349a69c3395f1a57c642dc62Ying Wang the Free Software Foundation; either version 3 of the License, or 705436638acc7c010349a69c3395f1a57c642dc62Ying Wang (at your option) any later version. 805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 905436638acc7c010349a69c3395f1a57c642dc62Ying Wang This program is distributed in the hope that it will be useful, 1005436638acc7c010349a69c3395f1a57c642dc62Ying Wang but WITHOUT ANY WARRANTY; without even the implied warranty of 1105436638acc7c010349a69c3395f1a57c642dc62Ying Wang MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1205436638acc7c010349a69c3395f1a57c642dc62Ying Wang GNU General Public License for more details. 1305436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1405436638acc7c010349a69c3395f1a57c642dc62Ying Wang You should have received a copy of the GNU General Public License 1505436638acc7c010349a69c3395f1a57c642dc62Ying Wang along with this program. If not, see <http://www.gnu.org/licenses/>. */ 1605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1705436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Written by Bruno Haible <bruno@clisp.org>, 2007. */ 1805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 1905436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* If the user's config.h happens to include <stdio.h>, let it include only 2005436638acc7c010349a69c3395f1a57c642dc62Ying Wang the system's <stdio.h> here, so that orig_fopen doesn't recurse to 2105436638acc7c010349a69c3395f1a57c642dc62Ying Wang rpl_fopen. */ 2205436638acc7c010349a69c3395f1a57c642dc62Ying Wang#define __need_FILE 2305436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <config.h> 2405436638acc7c010349a69c3395f1a57c642dc62Ying Wang 2505436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Get the original definition of fopen. It might be defined as a macro. */ 2605436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <stdio.h> 2705436638acc7c010349a69c3395f1a57c642dc62Ying Wang#undef __need_FILE 2805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 2905436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic FILE * 3005436638acc7c010349a69c3395f1a57c642dc62Ying Wangorig_fopen (const char *filename, const char *mode) 3105436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 3205436638acc7c010349a69c3395f1a57c642dc62Ying Wang return fopen (filename, mode); 3305436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 3405436638acc7c010349a69c3395f1a57c642dc62Ying Wang 3505436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Specification. */ 3605436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Write "stdio.h" here, not <stdio.h>, otherwise OSF/1 5.1 DTK cc eliminates 3705436638acc7c010349a69c3395f1a57c642dc62Ying Wang this include because of the preliminary #include <stdio.h> above. */ 3805436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include "stdio.h" 3905436638acc7c010349a69c3395f1a57c642dc62Ying Wang 4005436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <errno.h> 4105436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <fcntl.h> 4205436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <string.h> 4305436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <unistd.h> 4405436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <sys/types.h> 4505436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <sys/stat.h> 4605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 4705436638acc7c010349a69c3395f1a57c642dc62Ying WangFILE * 4805436638acc7c010349a69c3395f1a57c642dc62Ying Wangrpl_fopen (const char *filename, const char *mode) 4905436638acc7c010349a69c3395f1a57c642dc62Ying Wang{ 5005436638acc7c010349a69c3395f1a57c642dc62Ying Wang#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ 5105436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (strcmp (filename, "/dev/null") == 0) 5205436638acc7c010349a69c3395f1a57c642dc62Ying Wang filename = "NUL"; 5305436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif 5405436638acc7c010349a69c3395f1a57c642dc62Ying Wang 5505436638acc7c010349a69c3395f1a57c642dc62Ying Wang#if FOPEN_TRAILING_SLASH_BUG 5605436638acc7c010349a69c3395f1a57c642dc62Ying Wang /* If the filename ends in a slash and a mode that requires write access is 5705436638acc7c010349a69c3395f1a57c642dc62Ying Wang specified, then fail. 5805436638acc7c010349a69c3395f1a57c642dc62Ying Wang Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html> 5905436638acc7c010349a69c3395f1a57c642dc62Ying Wang says that 6005436638acc7c010349a69c3395f1a57c642dc62Ying Wang "A pathname that contains at least one non-slash character and that 6105436638acc7c010349a69c3395f1a57c642dc62Ying Wang ends with one or more trailing slashes shall be resolved as if a 6205436638acc7c010349a69c3395f1a57c642dc62Ying Wang single dot character ( '.' ) were appended to the pathname." 6305436638acc7c010349a69c3395f1a57c642dc62Ying Wang and 6405436638acc7c010349a69c3395f1a57c642dc62Ying Wang "The special filename dot shall refer to the directory specified by 6505436638acc7c010349a69c3395f1a57c642dc62Ying Wang its predecessor." 6605436638acc7c010349a69c3395f1a57c642dc62Ying Wang If the named file already exists as a directory, then if a mode that 6705436638acc7c010349a69c3395f1a57c642dc62Ying Wang requires write access is specified, fopen() must fail because POSIX 6805436638acc7c010349a69c3395f1a57c642dc62Ying Wang <http://www.opengroup.org/susv3/functions/fopen.html> says that it 6905436638acc7c010349a69c3395f1a57c642dc62Ying Wang fails with errno = EISDIR in this case. 7005436638acc7c010349a69c3395f1a57c642dc62Ying Wang If the named file does not exist or does not name a directory, then 7105436638acc7c010349a69c3395f1a57c642dc62Ying Wang fopen() must fail since the file does not contain a '.' directory. */ 7205436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 7305436638acc7c010349a69c3395f1a57c642dc62Ying Wang size_t len = strlen (filename); 7405436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (len > 0 && filename[len - 1] == '/') 7505436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 7605436638acc7c010349a69c3395f1a57c642dc62Ying Wang int fd; 7705436638acc7c010349a69c3395f1a57c642dc62Ying Wang struct stat statbuf; 7805436638acc7c010349a69c3395f1a57c642dc62Ying Wang FILE *fp; 7905436638acc7c010349a69c3395f1a57c642dc62Ying Wang 8005436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (mode[0] == 'w' || mode[0] == 'a') 8105436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 8205436638acc7c010349a69c3395f1a57c642dc62Ying Wang errno = EISDIR; 8305436638acc7c010349a69c3395f1a57c642dc62Ying Wang return NULL; 8405436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 8505436638acc7c010349a69c3395f1a57c642dc62Ying Wang 8605436638acc7c010349a69c3395f1a57c642dc62Ying Wang fd = open (filename, O_RDONLY); 8705436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (fd < 0) 8805436638acc7c010349a69c3395f1a57c642dc62Ying Wang return NULL; 8905436638acc7c010349a69c3395f1a57c642dc62Ying Wang 9005436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode)) 9105436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 9205436638acc7c010349a69c3395f1a57c642dc62Ying Wang close (fd); 9305436638acc7c010349a69c3395f1a57c642dc62Ying Wang errno = ENOTDIR; 9405436638acc7c010349a69c3395f1a57c642dc62Ying Wang return NULL; 9505436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 9605436638acc7c010349a69c3395f1a57c642dc62Ying Wang 9705436638acc7c010349a69c3395f1a57c642dc62Ying Wang fp = fdopen (fd, mode); 9805436638acc7c010349a69c3395f1a57c642dc62Ying Wang if (fp == NULL) 9905436638acc7c010349a69c3395f1a57c642dc62Ying Wang { 10005436638acc7c010349a69c3395f1a57c642dc62Ying Wang int saved_errno = errno; 10105436638acc7c010349a69c3395f1a57c642dc62Ying Wang close (fd); 10205436638acc7c010349a69c3395f1a57c642dc62Ying Wang errno = saved_errno; 10305436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 10405436638acc7c010349a69c3395f1a57c642dc62Ying Wang return fp; 10505436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 10605436638acc7c010349a69c3395f1a57c642dc62Ying Wang } 10705436638acc7c010349a69c3395f1a57c642dc62Ying Wang# endif 10805436638acc7c010349a69c3395f1a57c642dc62Ying Wang 10905436638acc7c010349a69c3395f1a57c642dc62Ying Wang return orig_fopen (filename, mode); 11005436638acc7c010349a69c3395f1a57c642dc62Ying Wang} 111