Rename stdio_.h to stdio.in.h.

[gnulib.git] / lib / lstat.c

diff --git a/lib/lstat.c b/lib/lstat.c
index 4e22097..77dd228 100644 (file)
--- a/lib/lstat.c
+++ b/lib/lstat.c
@@ -1,7 +1,7 @@
-/* Work around the bug in some systems whereby lstat succeeds when
-   given the zero-length file name argument.  The lstat from SunOS4.1.4
-   has this bug.
-   Copyright (C) 1997 Free Software Foundation, Inc.
+/* Work around a bug of lstat on some systems
+
+   Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 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
@@ -15,36 +15,62 @@
 
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
 /* written by Jim Meyering */
 
 #include <config.h>
 
-/* Disable the definition of lstat to rpl_lstat (from config.h) in this
-   file.  Otherwise, we'd get conflicting prototypes for rpl_lstat on
-   most systems.  */
-#undef lstat
+/* The specification of these functions is in sys_stat.h.  But we cannot
+   include this include file here, because on some systems, a
+   "#define lstat lstat64" is being used, and sys_stat.h deletes this
+   definition.  */
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <string.h>
 #include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
 
-/* FIXME: describe.  */
+/* lstat works differently on Linux and Solaris systems.  POSIX (see
+   `pathname resolution' in the glossary) requires that programs like
+   `ls' take into consideration the fact that FILE has a trailing slash
+   when FILE is a symbolic link.  On Linux and Solaris 10 systems, the
+   lstat function already has the desired semantics (in treating
+   `lstat ("symlink/", sbuf)' just like `lstat ("symlink/.", sbuf)',
+   but on Solaris 9 and earlier it does not.
+
+   If FILE has a trailing slash and specifies a symbolic link,
+   then use stat() to get more info on the referent of FILE.
+   If the referent is a non-directory, then set errno to ENOTDIR
+   and return -1.  Otherwise, return stat's result.  */
 
 int
-rpl_lstat (file, sbuf)
-     const char *file;
-     struct stat *sbuf;
+rpl_lstat (const char *file, struct stat *sbuf)
 {
-  if (file && *file == 0)
-    {
-      errno = EINVAL;
-      return -1;
-    }
+  size_t len;
+  int lstat_result = lstat (file, sbuf);
+
+  if (lstat_result != 0 || !S_ISLNK (sbuf->st_mode))
+    return lstat_result;
+
+  len = strlen (file);
+  if (len == 0 || file[len - 1] != '/')
+    return 0;
+
+  /* FILE refers to a symbolic link and the name ends with a slash.
+     Call stat() to get info about the link's referent.  */
+
+  /* If stat fails, then we do the same.  */
+  if (stat (file, sbuf) != 0)
+    return -1;
+
+  /* If FILE references a directory, return 0.  */
+  if (S_ISDIR (sbuf->st_mode))
+    return 0;
 
-  return lstat (file, sbuf);
+  /* Here, we know stat succeeded and FILE references a non-directory.
+     But it was specified via a name including a trailing slash.
+     Fail with errno set to ENOTDIR to indicate the contradiction.  */
+  errno = ENOTDIR;
+  return -1;
 }