maint: update copyright

[gnulib.git] / lib / fopen.c

diff --git a/lib/fopen.c b/lib/fopen.c
index fd5564c..8fead5a 100644 (file)
--- a/lib/fopen.c
+++ b/lib/fopen.c
@@ -1,5 +1,5 @@
 /* Open a stream to a file.
-   Copyright (C) 2007 Free Software Foundation, Inc.
+   Copyright (C) 2007-2014 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
@@ -16,21 +16,95 @@
 
 /* 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>
 
-/* Specification.  */
+/* 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 *
-fopen (const char *filename, const char *mode)
-#undef fopen
+rpl_fopen (const char *filename, const char *mode)
 {
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
   if (strcmp (filename, "/dev/null") == 0)
     filename = "NUL";
 #endif
 
-  return fopen (filename, mode);
+#if FOPEN_TRAILING_SLASH_BUG
+  /* If the filename ends in a slash and a mode that requires write access is
+     specified, then fail.
+     Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
+     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."
+     and
+       "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
+     <http://www.opengroup.org/susv3/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);
 }