X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxreadlink.c;h=4fdcafb56cb17a9eda78d6380aac8bfc4dd21368;hb=46da792f2ddd95bb06ffb9e08d0f2e921b90772f;hp=54b5e9e5970fff0e39cacdeb7d8b799610cafcc5;hpb=8b8ff236fe4bd09b2cdbd5d26909a008d342a695;p=gnulib.git

diff --git a/lib/xreadlink.c b/lib/xreadlink.c
index 54b5e9e59..4fdcafb56 100644
--- a/lib/xreadlink.c
+++ b/lib/xreadlink.c
@@ -1,11 +1,11 @@
 /* xreadlink.c -- readlink wrapper to return the link name in malloc'd storage
 
-   Copyright 2001 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2003-2007, 2009-2010 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   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.
+   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
@@ -13,80 +13,32 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; see the file COPYING.
-   If not, write to the Free Software Foundation,
-   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-/* Written by Jim Meyering <jim@meyering.net>  */
+/* Written by Jim Meyering <jim@meyering.net>
+   and Bruno Haible <bruno@clisp.org>.  */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
-#include <stdio.h>
-#include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
-
-#if HAVE_LIMITS_H
-# include <limits.h>
-#endif
-#if HAVE_SYS_TYPES_H
-# include <sys/types.h>
-#endif
-#if HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+/* Specification.  */
+#include "xreadlink.h"
 
-#ifndef SIZE_MAX
-# define SIZE_MAX ((size_t) -1)
-#endif
-#ifndef SSIZE_MAX
-# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
-#endif
+#include <errno.h>
 
+#include "areadlink.h"
 #include "xalloc.h"
-#include "xreadlink.h"
 
 /* Call readlink to get the symbolic link value of FILENAME.
    Return a pointer to that NUL-terminated string in malloc'd storage.
-   If readlink fails, return NULL (caller may use errno to diagnose).
+   If readlink fails, return NULL and set errno.
    If realloc fails, or if the link value is longer than SIZE_MAX :-),
    give a diagnostic and exit.  */
 
 char *
 xreadlink (char const *filename)
 {
-  /* The initial buffer size for the link value.  A power of 2
-     detects arithmetic overflow earlier, but is not required.  */
-  size_t buf_size = 128;
-
-  while (1)
-    {
-      char *buffer = xmalloc (buf_size);
-      ssize_t link_length = readlink (filename, buffer, buf_size);
-
-      if (link_length < 0)
-	{
-	  int saved_errno = errno;
-	  free (buffer);
-	  errno = saved_errno;
-	  return NULL;
-	}
-
-      if ((size_t) link_length < buf_size)
-	{
-	  buffer[link_length] = 0;
-	  return buffer;
-	}
-
-      free (buffer);
-      buf_size *= 2;
-      if (SSIZE_MAX < buf_size || (SIZE_MAX / 2 < SSIZE_MAX && buf_size == 0))
-	xalloc_die ();
-    }
+  char *result = areadlink (filename);
+  if (result == NULL && errno == ENOMEM)
+    xalloc_die ();
+  return result;
 }