tar-1.29HEADtar-1.29master

1 files changed, 56 insertions, 0 deletions

diff --git a/gnu/areadlink.c b/gnu/areadlink.c
new file mode 100644
index 0000000..248cc6b
--- /dev/null
+++ b/gnu/areadlink.c
@@ -0,0 +1,56 @@
+/* areadlink.c -- readlink wrapper to return the link name in malloc'd storage
+   Unlike xreadlink and xreadlink_with_size, don't ever call exit.
+
+   Copyright (C) 2001, 2003-2007, 2009-2015 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 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
+   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, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Jim Meyering <jim@meyering.net>
+   and Bruno Haible <bruno@clisp.org>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "areadlink.h"
+
+#include "careadlinkat.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+
+/* Get the symbolic link value of FILENAME and put it into BUFFER, with
+   size BUFFER_SIZE.  This function acts like readlink but has
+   readlinkat's signature.  */
+static ssize_t
+careadlinkatcwd (int fd, char const *filename, char *buffer,
+                 size_t buffer_size)
+{
+  /* FD must be AT_FDCWD here, otherwise the caller is using this
+     function in contexts it was not meant for.  */
+  if (fd != AT_FDCWD)
+    abort ();
+  return readlink (filename, buffer, buffer_size);
+}
+
+/* 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 and set errno.
+   If allocation fails, or if the link value is longer than SIZE_MAX :-),
+   return NULL and set errno to ENOMEM.  */
+
+char *
+areadlink (char const *filename)
+{
+  return careadlinkat (AT_FDCWD, filename, NULL, 0, NULL, careadlinkatcwd);
+}