X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxreadlink.c;h=1ec818e113924637e915d321b4beb2fba563a5bb;hb=d43b4675e20324bf187ca42bc27233f832449282;hp=baea5b9cfbdb7b2204f39b1036c693afe9e96033;hpb=662e273931461d8aed89f64ea9ceb1618916e180;p=gnulib.git

diff --git a/lib/xreadlink.c b/lib/xreadlink.c
index baea5b9cf..1ec818e11 100644
--- a/lib/xreadlink.c
+++ b/lib/xreadlink.c
@@ -1,12 +1,11 @@
 /* xreadlink.c -- readlink wrapper to return the link name in malloc'd storage
 
-   Copyright (C) 2001, 2003, 2004, 2005, 2006 Free Software
-   Foundation, Inc.
+   Copyright (C) 2001, 2003-2007 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
@@ -14,92 +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,
-   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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>.  */
 
 #include <config.h>
 
+/* Specification.  */
 #include "xreadlink.h"
 
-#include <stdio.h>
 #include <errno.h>
-#include <limits.h>
-#include <sys/types.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-#ifndef SIZE_MAX
-# define SIZE_MAX ((size_t) -1)
-#endif
-#ifndef SSIZE_MAX
-# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
-#endif
-
-/* SYMLINK_MAX is used only for an initial memory-allocation sanity
-   check, so it's OK to guess too small on hosts where there is no
-   arbitrary limit to symbolic link length.  */
-#ifndef SYMLINK_MAX
-# define SYMLINK_MAX 1024
-#endif
-
-#define MAXSIZE (SIZE_MAX < SSIZE_MAX ? SIZE_MAX : SSIZE_MAX)
 
+#include "areadlink.h"
 #include "xalloc.h"
 
-/* Call readlink to get the symbolic link value of FILE.
-   SIZE is a hint as to how long the link is expected to be;
-   typically it is taken from st_size.  It need not be correct.
+/* 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 malloc fails, or if the link value is longer than SSIZE_MAX :-),
+   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 *file, size_t size)
+xreadlink (char const *filename)
 {
-  /* Some buggy file systems report garbage in st_size.  Defend
-     against them by ignoring outlandish st_size values in the initial
-     memory allocation.  */
-  size_t symlink_max = SYMLINK_MAX;
-  size_t INITIAL_LIMIT_BOUND = 8 * 1024;
-  size_t initial_limit = (symlink_max < INITIAL_LIMIT_BOUND
-			  ? symlink_max + 1
-			  : INITIAL_LIMIT_BOUND);
-
-  /* The initial buffer size for the link value.  */
-  size_t buf_size = size < initial_limit ? size + 1 : initial_limit;
-
-  while (1)
-    {
-      char *buffer = xmalloc (buf_size);
-      ssize_t r = readlink (file, buffer, buf_size);
-      size_t link_length = r;
-
-      /* On AIX 5L v5.3 and HP-UX 11i v2 04/09, readlink returns -1
-	 with errno == ERANGE if the buffer is too small.  */
-      if (r < 0 && errno != ERANGE)
-	{
-	  int saved_errno = errno;
-	  free (buffer);
-	  errno = saved_errno;
-	  return NULL;
-	}
-
-      if (link_length < buf_size)
-	{
-	  buffer[link_length] = 0;
-	  return buffer;
-	}
-
-      free (buffer);
-      if (buf_size <= MAXSIZE / 2)
-	buf_size *= 2;
-      else if (buf_size < MAXSIZE)
-	buf_size = MAXSIZE;
-      else
-	xalloc_die ();
-    }
+  char *result = areadlink (filename);
+  if (result == NULL && errno == ENOMEM)
+    xalloc_die ();
+  return result;
 }