Re: stat and lstat should define their replacements

[Derek Price]

Paul Eggert wrote:

>Derek Price <address@hidden> writes:
>
>  
>
>>What does this mean for Bruno's recent patch for stat & lstat which
>>removed the SunOS 4.1.4 support in addition to some other fixes?
>>    
>>
>
>His patch made sense to me, but as far as I know nobody has taken the
>time to integrate the comments on it and try it out.  Here's what I
>see so far:
>  
>

I've attached a revised patch.  In addition to integrating the
suggestions Bruno's patch received, it also includes changes to
modules/lstat, config/srclist.txt, and MODULES.html.sh.  In addition to
this patch, lib/stat.c, m4/stat.m4, and modules/stat need to be removed.

It appears to work installed in CVS on Linux, but that only tests the
modules file and macro, not the C source or header files.

Cheers,

Derek

Index: MODULES.html.sh
===================================================================
RCS file: /cvsroot/gnulib/gnulib/MODULES.html.sh,v
retrieving revision 1.88
diff -u -p -r1.88 MODULES.html.sh
--- MODULES.html.sh     2 Jun 2005 20:41:04 -0000       1.88
+++ MODULES.html.sh     7 Jun 2005 14:46:02 -0000
@@ -1063,7 +1063,6 @@ srand
 srand48
 srandom
 sscanf
-stat
 statvfs
 stdin
 strcasecmp
@@ -1756,7 +1755,6 @@ func_all_modules ()
   func_module mkdtemp
   func_module poll
   func_module readlink
-  func_module stat
   func_module lstat
   func_module time_r
   func_module timespec
Index: config/srclist.txt
===================================================================
RCS file: /cvsroot/gnulib/gnulib/config/srclist.txt,v
retrieving revision 1.63
diff -u -p -r1.63 srclist.txt
--- config/srclist.txt  29 May 2005 16:56:02 -0000      1.63
+++ config/srclist.txt  7 Jun 2005 14:46:02 -0000
@@ -143,7 +143,6 @@ $LIBCSRC/sysdeps/generic/memmem.c   lib gp
 #
 # These implementations are quite different.
 #$LIBCSRC/io/lstat.c                           lib gpl
-#$LIBCSRC/io/stat.c                            lib gpl
 #$LIBCSRC/libio/__fpending.c                   lib gpl
 #$LIBCSRC/malloc/malloc.c                      lib gpl
 #$LIBCSRC/misc/dirname.c                       lib gpl
Index: lib/lstat.c
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/lstat.c,v
retrieving revision 1.7
diff -u -p -r1.7 lstat.c
--- lib/lstat.c 14 May 2005 06:03:58 -0000      1.7
+++ lib/lstat.c 7 Jun 2005 14:46:02 -0000
@@ -1,8 +1,6 @@
-/* Work around the bug in some systems whereby lstat succeeds when
-   given the zero-length file name argument.  The lstat from SunOS 4.1.4
-   has this bug.
+/* Work around a bug of lstat on some systems
 
-   Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003 Free
+   Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free
    Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
@@ -19,5 +17,59 @@
    along with this program; if not, write to the Free Software Foundation,
    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#define LSTAT
-#include "stat.c"
+/* written by Jim Meyering */
+
+#include <config.h>
+
+/* 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 <stdlib.h>
+#include <string.h>
+
+#include "stat-macros.h"
+#include "xalloc.h"
+
+/* 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 systems, the lstat function already
+   has the desired semantics (in treating `lstat("symlink/",sbuf)' just like
+   `lstat("symlink/.",sbuf)', but on Solaris it does not.
+
+   If FILE has a trailing slash and specifies a symbolic link,
+   then append a `.' to FILE and call lstat a second time.  */
+
+int
+rpl_lstat (const char *file, struct stat *sbuf)
+{
+  size_t len;
+  char *new_file;
+
+  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 lstat_result;
+
+  /* FILE refers to a symbolic link and the name ends with a slash.
+     Append a `.' to FILE and repeat the lstat call.  */
+
+  /* Add one for the `.' we'll append, and one more for the trailing NUL.  */
+  new_file = xmalloc (len + 1 + 1);
+  memcpy (new_file, file, len);
+  new_file[len] = '.';
+  new_file[len + 1] = 0;
+
+  lstat_result = lstat (new_file, sbuf);
+  free (new_file);
+
+  return lstat_result;
+}
Index: lib/lstat.h
===================================================================
RCS file: lib/lstat.h
diff -N lib/lstat.h
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ lib/lstat.h 7 Jun 2005 14:46:02 -0000
@@ -0,0 +1,24 @@
+/* Retrieving information about files.
+   Copyright (C) 2005 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 2, 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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <sys/stat.h>
+
+#if !LSTAT_FOLLOWS_SLASHED_SYMLINK
+extern int rpl_lstat (const char *name, struct stat *buf);
+# undef lstat
+# define lstat rpl_lstat
+#endif
Index: m4/lstat.m4
===================================================================
RCS file: /cvsroot/gnulib/gnulib/m4/lstat.m4,v
retrieving revision 1.20
diff -u -p -r1.20 lstat.m4
--- m4/lstat.m4 2 May 2005 07:00:50 -0000       1.20
+++ m4/lstat.m4 7 Jun 2005 14:46:02 -0000
@@ -18,7 +18,7 @@ dnl
 
 AC_DEFUN([gl_FUNC_LSTAT],
 [
-  AC_REQUIRE([AC_FUNC_LSTAT])
-  dnl Note: AC_FUNC_LSTAT does AC_LIBOBJ(lstat).
+  AC_REQUIRE([AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
+  dnl Note: AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK does AC_LIBOBJ(lstat).
   :
 ])
Index: modules/lstat
===================================================================
RCS file: /cvsroot/gnulib/gnulib/modules/lstat,v
retrieving revision 1.6
diff -u -p -r1.6 lstat
--- modules/lstat       2 May 2005 07:00:50 -0000       1.6
+++ modules/lstat       7 Jun 2005 14:46:02 -0000
@@ -1,12 +1,14 @@
 Description:
-stat() function: return information about a file or symbolic link.
+lstat() function: return information about a file or symbolic link.
 
 Files:
 lib/lstat.c
+lib/lstat.h
 m4/lstat.m4
 
 Depends-on:
-stat
+xalloc
+stat-macros
 
 configure.ac:
 gl_FUNC_LSTAT
@@ -14,7 +16,7 @@ gl_FUNC_LSTAT
 Makefile.am:
 
 Include:
-<sys/stat.h>
+"lstat.h"
 
 License:
 GPL