Added ch and pwd to NSH

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@841 42af7a65-404d-4744-a932-0658087f49c3

5 files changed, 110 insertions, 160 deletions

diff --git a/nuttx/lib/Makefile b/nuttx/lib/Makefile
index cf35a0541..a56cde66f 100644
--- a/nuttx/lib/Makefile
+++ b/nuttx/lib/Makefile
@@ -57,7 +57,7 @@ STDIO_SRCS	= lib_printf.c lib_rawprintf.c lib_lowprintf.c lib_dbg.c \
 		  lib_lowstream.c lib_nullstream.c lib_sscanf.c
 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
-STDIO_SRCS	+= lib_rawstream.c lib_chdir.c lib_getcwd.c lib_cwdsem.c
+STDIO_SRCS	+= lib_rawstream.c
 ifneq ($(CONFIG_NFILE_STREAMS),0)
 STDIO_SRCS	+= lib_fopen.c lib_fclose.c lib_fread.c lib_libfread.c lib_fseek.c \
 		   lib_fgetc.c lib_fgets.c lib_gets.c lib_fwrite.c lib_libfwrite.c \
@@ -72,6 +72,11 @@ STDLIB_SRCS	= lib_rand.c
 MATH_SRCS	= lib_rint.c
 
 UNISTD_SRCS	= lib_getopt.c
+ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
+ifneq ($(CONFIG_DISABLE_ENVIRON),y)
+UNISTD_SRCS	+=  lib_chdir.c lib_getcwd.c
+endif
+endif
 
 NET_SRCS	= lib_htons.c lib_htonl.c lib_inetntoa.c lib_etherntoa.c
 
diff --git a/nuttx/lib/lib_chdir.c b/nuttx/lib/lib_chdir.c
index 008e923ec..0db29829d 100644
--- a/nuttx/lib/lib_chdir.c
+++ b/nuttx/lib/lib_chdir.c
@@ -40,6 +40,8 @@
 #include <nuttx/config.h>
 
 #include <sys/types.h>
+#include <sys/stat.h>
+
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -47,13 +49,35 @@
 
 #include "lib_internal.h"
 
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+
 /****************************************************************************
  * Public Variables
  ****************************************************************************/
 
-#if CONFIG_NFILE_DESCRIPTORS > 0
-char *g_cwd     = NULL;
-char *g_prevcwd = NULL;
+/****************************************************************************
+ * 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
@@ -94,38 +118,64 @@ char *g_prevcwd = NULL;
 
 int chdir(FAR const char *path)
 {
-  char *duppath;
+  struct stat buf;
+  char *oldpwd;
+  char *alloc;
+  int err;
+  int ret;
 
   /* Verify the input parameters */
 
   if (!path)
     {
-      errno = ENOENT;
-      return ERROR;
+      err = ENOENT;
+      goto errout;
     }
 
   /* Verify that 'path' refers to a directory */
-  /* (To be provided) */
 
-  /* Make a persistent copy of 'path' */
+  ret = stat(path, &buf);
+  if (ret != 0)
+    {
+      err = ENOENT;
+      goto errout;
+    }
+
+  /* Something exists here... is it a directory? */
 
-  duppath = strdup(path);
+  if (!S_ISDIR(buf.st_mode))
+    {
+      err = ENOTDIR;
+      goto errout;
+    }
 
-  /* Free any preceding cwd and set the previous to the cwd (this
-   * is to support 'cd -' in NSH
+  /* 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)
    */
 
-  cwd_semtake();
-  if (g_prevcwd)
+  sched_lock();
+  oldpwd = getenv("PWD");
+  if (!oldpwd)
     {
-      free(g_prevcwd);
+      oldpwd = CONFIG_LIB_HOMEDIR;
     }
-  g_prevcwd = g_cwd;
 
-  /* Set the cwd to a persistent copy of the input 'path' */
+  alloc = strdup(oldpwd);  /* kludge needed because environment is realloc'ed */
+  setenv("OLDPWD", alloc, TRUE);
+  free(alloc);
 
-  g_cwd = duppath;
-  cwd_semgive();
+  /* Set the cwd to the input 'path' */
+
+  setenv("PWD", path, TRUE);
+  sched_unlock();
   return OK;
+
+errout:
+  errno = err;
+  return ERROR;
 }
-#endif /* CONFIG_NFILE_DESCRIPTORS */
+#endif /* CONFIG_NFILE_DESCRIPTORS && !CONFIG_DISABLE_ENVIRON */
diff --git a/nuttx/lib/lib_cwdsem.c b/nuttx/lib/lib_cwdsem.c
deleted file mode 100644
index d06487890..000000000
--- a/nuttx/lib/lib_cwdsem.c
+++ /dev/null
@@ -1,86 +0,0 @@
-/****************************************************************************
- * lib/lib_cwdsem.c
- *
- *   Copyright (C) 2008 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/types.h>
-#include <unistd.h>
-#include <assert.h>
-#include <semaphore.h>
-#include <errno.h>
-
-/****************************************************************************
- * Private Variables
- ****************************************************************************/
-
-#if CONFIG_NFILE_DESCRIPTORS > 0
-static sem_t g_cwdsem  = { 1 };
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
-/****************************************************************************
- * Name: cwd_semtake
- ****************************************************************************/
-
-void cwd_semtake(void)
-{
-  /* Take the semaphore (perhaps waiting) */
-
-  while (sem_wait(&g_cwdsem) != 0)
-    {
-      /* The only case that an error should occr here is if the wait was
-       * awakened by a signal.
-       */
-
-      ASSERT(errno == EINTR);
-    }
-}
-/****************************************************************************
- * Name: cwd_semgive
- ****************************************************************************/
-
-void cwd_semgive(void)
-{
-  /* Give the semaphore */
-
-  (void)sem_post(&g_cwdsem);
-}
-#endif /* CONFIG_NFILE_DESCRIPTORS */
diff --git a/nuttx/lib/lib_getcwd.c b/nuttx/lib/lib_getcwd.c
index a0db05c09..20f7cef48 100644
--- a/nuttx/lib/lib_getcwd.c
+++ b/nuttx/lib/lib_getcwd.c
@@ -40,12 +40,15 @@
 #include <nuttx/config.h>
 
 #include <sys/types.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)
+
 /****************************************************************************
  * Definitions
  ****************************************************************************/
@@ -90,50 +93,38 @@
  *
  ****************************************************************************/
 
-#if CONFIG_NFILE_DESCRIPTORS > 0
 FAR char *getcwd(FAR char *buf, size_t size)
 {
-    const char *ptr;
-    int err;
-
-    /* Verify input parameters */
-
-    if (!buf || !size)
-      {
-        err = EINVAL;
-        goto errout;
-      }
-
-    /* If no working directory is defined, then default to the home directory */
-
-    cwd_semtake();
-    if (g_cwd)
-      {
-        ptr = g_cwd;
-      }
-    else
-      {
-        ptr = CONFIG_LIB_HOMEDIR;
-      }
-
-    /* Verify that the cwd will fit into the user-provided buffer */
-
-    if (strlen(ptr) + 1 > size)
-      {
-        err = ERANGE;
-        goto errout_with_sem;
-      }
-
-   /* Copy the cwd to the user buffer */
-
-   strcpy(buf, ptr);
-   cwd_semgive();
-   return buf;
-
-errout_with_sem:
-  cwd_semgive();
-errout:
-  errno = err;
-  return NULL;
+  char *pwd;
+
+  /* Verify input parameters */
+
+  if (!buf || !size)
+    {
+      errno = EINVAL;
+      return NULL;
+    }
+
+  /* If no working directory is defined, then default to the home directory */
+
+  pwd = getenv("PWD");
+  if (!pwd)
+    {
+      pwd = CONFIG_LIB_HOMEDIR;
+    }
+
+  /* Verify that the cwd will fit into the user-provided buffer */
+
+  if (strlen(pwd) + 1 > size)
+    {
+      errno = ERANGE;
+      return NULL;
+    }
+
+  /* Copy the cwd to the user buffer */
+
+  strcpy(buf, pwd);
+  sched_unlock();
+  return buf;
 }
-#endif /* CONFIG_NFILE_DESCRIPTORS */
+#endif /* CONFIG_NFILE_DESCRIPTORS && !CONFIG_DISABLE_ENVIRON */
diff --git a/nuttx/lib/lib_internal.h b/nuttx/lib/lib_internal.h
index 067b64c24..2f776321a 100644
--- a/nuttx/lib/lib_internal.h
+++ b/nuttx/lib/lib_internal.h
@@ -102,11 +102,6 @@ struct lib_rawstream_s
  * Public Variables
  ****************************************************************************/
  
-#if CONFIG_NFILE_DESCRIPTORS > 0
-extern char *g_cwd;            /* Defined in lib_chdir.c */
-extern char *g_prevcwd;        /* Defined in lib_chdir.c */
-#endif
-
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
@@ -193,9 +188,4 @@ extern void lib_give_semaphore(FAR struct file_struct *stream);
 
 extern int lib_getbase(const char *nptr, const char **endptr);
 
-/* Defined in lib_cwdsem.c */
-
-extern void cwd_semtake(void);
-extern void cwd_semgive(void);
-
 #endif /* __LIB_INTERNAL_H */