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authorJim Meyering <jim@meyering.net>2003-03-04 18:00:42 +0000
committerJim Meyering <jim@meyering.net>2003-03-04 18:00:42 +0000
commitd7b57a757102787dd9589153d4abe15b1fd05082 (patch)
tree76b7bcf900f5c6177ac8674729f72669ea8bcf44 /lib/getcwd.c
parent4b7f5815ef7dfa25413f64574569c74fe68d765a (diff)
downloadcoreutils-d7b57a757102787dd9589153d4abe15b1fd05082.tar.xz
*** empty log message ***
Diffstat (limited to 'lib/getcwd.c')
-rw-r--r--lib/getcwd.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/lib/getcwd.c b/lib/getcwd.c
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+/* Provide a replacement for the POSIX getcwd function.
+ Copyright (C) 2003 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+/* written by Jim Meyering */
+
+#include <config.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#include <sys/types.h>
+
+#include "pathmax.h"
+#include "same.h"
+
+/* Undefine getcwd here so any prototype is not redefined to be a
+ prototype for rpl_getcwd. */
+#undef getcwd
+
+/* Guess high, because that makes the test below more conservative.
+ But this is a kludge, because we should really use
+ pathconf (".", _PC_NAME_MAX). But it's probably not worth the cost. */
+#define KLUDGE_POSIX_NAME_MAX 255
+
+#define MAX_SAFE_LEN (PATH_MAX - 1 - KLUDGE_POSIX_NAME_MAX - 1)
+
+/* This is a wrapper for getcwd.
+ Some implementations (at least GNU libc 2.3.1) return non-NULL
+ for a working directory name longer than PATH_MAX, yet the returned
+ string is a strict prefix of the desired directory name.
+ Upon such a failure, free the offending string, set errno to
+ ENAMETOOLONG, and return NULL. */
+
+char *
+rpl_getcwd (char *buf, size_t size)
+{
+ char *cwd = getcwd (buf, size);
+
+ if (cwd == NULL)
+ return NULL;
+
+ if (strlen (cwd) <= MAX_SAFE_LEN || same_name (cwd, "."))
+ return cwd;
+
+ free (cwd);
+ errno = ENAMETOOLONG;
+ return NULL;
+}