1 files changed, 179 insertions, 0 deletions
diff --git a/nuttx/lib/unistd/lib_chdir.c b/nuttx/lib/unistd/lib_chdir.c
new file mode 100644
index 000000000..15dc64383
--- /dev/null
+++ b/nuttx/lib/unistd/lib_chdir.c
@@ -0,0 +1,179 @@
+/****************************************************************************
+ * lib/unistd/lib_chdir.c
+ *
+ *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "lib_internal.h"
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: _trimdir
+ ****************************************************************************/
+
+#if 0
+static inline void _trimdir(char *path)
+{
+ /* Skip any trailing '/' characters (unless it is also the leading '/') */
+
+ int len = strlen(path) - 1;
+ while (len > 0 && path[len] == '/')
+   {
+      path[len] = '\0';
+      len--;
+   }
+}
+#else
+#  define _trimdir(p)
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: chdir
+ *
+ * Description:
+ *   The chdir() function causes the directory named by the pathname pointed
+ *   to by the 'path' argument to become the current working directory; that
+ *   is, the starting point for path searches for pathnames not beginning
+ *   with '/'.
+ *
+ * Input Parmeters:
+ *   path - A pointer to a directory to use as the new current working
+ *     directory
+ *
+ * Returned Value:
+ *   0(OK) on success; -1(ERROR) on failure with errno set appropriately:
+ *
+ *   EACCES
+ *     Search permission is denied for any component of the pathname.
+ *   ELOOP
+ *     A loop exists in symbolic links encountered during resolution of the
+ *     'path' argument OR more that SYMLOOP_MAX symbolic links in the
+ *     resolution of the 'path' argument.
+ *   ENAMETOOLONG
+ *     The length of the path argument exceeds PATH_MAX or a pathname component
+ *     is longer than NAME_MAX.
+ *   ENOENT
+ *     A component of 'path' does not name an existing directory or path is
+ *     an empty string.
+ *   ENOTDIR
+ *     A component of the pathname is not a directory.
+ *
+ ****************************************************************************/
+
+int chdir(FAR const char *path)
+{
+  struct stat buf;
+  char *oldpwd;
+  char *alloc;
+  int err;
+  int ret;
+
+  /* Verify the input parameters */
+
+  if (!path)
+    {
+      err = ENOENT;
+      goto errout;
+    }
+
+  /* Verify that 'path' refers to a directory */
+
+  ret = stat(path, &buf);
+  if (ret != 0)
+    {
+      err = ENOENT;
+      goto errout;
+    }
+
+  /* Something exists here... is it a directory? */
+
+  if (!S_ISDIR(buf.st_mode))
+    {
+      err = ENOTDIR;
+      goto errout;
+    }
+
+  /* Yes, it is a directory. Remove any trailing '/' characters from the path */
+
+  _trimdir(path);
+
+  /* Replace any preceding OLDPWD with the current PWD (this is to
+   * support 'cd -' in NSH)
+   */
+
+  sched_lock();
+  oldpwd = getenv("PWD");
+  if (!oldpwd)
+    {
+      oldpwd = CONFIG_LIB_HOMEDIR;
+    }
+
+  alloc = strdup(oldpwd);  /* kludge needed because environment is realloc'ed */
+  setenv("OLDPWD", alloc, TRUE);
+  free(alloc);
+
+  /* Set the cwd to the input 'path' */
+
+  setenv("PWD", path, TRUE);
+  sched_unlock();
+  return OK;
+
+errout:
+  errno = err;
+  return ERROR;
+}
+#endif /* CONFIG_NFILE_DESCRIPTORS && !CONFIG_DISABLE_ENVIRON */