Added ch and pwd to NSH

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

ChangeLog

@@ -420,5 +420,7 @@
 	* Add chdir() and getcwd()
 	* Fix error in getopt() when called with argc==1
 	* Fix error in stat() when used on the root directory
+	* NSH: Add cd and pwd commands and current working directory to all NSH
+	  commands that refer to paths.
 
 

Documentation/NuttX.html

@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
-      <p>Last Updated: August 22, 2008</p>
+      <p>Last Updated: August 23, 2008</p>
     </td>
   </tr>
 </table>
@@ -1052,6 +1052,10 @@ nuttx-0.3.13 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 	* NSH now supports commands to inspect and modify memory
 	* NSH cat command now supports multiple files on command line
 	* Add chdir() and getcwd()
+	* Fix error in getopt() when called with argc==1
+	* Fix error in stat() when used on the root directory
+	* NSH: Add cd and pwd commands and current working directory to all NSH
+	  commands that refer to paths.
 
 pascal-0.1.3 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 

examples/README.txt

@@ -38,6 +38,7 @@ examples/nsh
   Command    Depends on Configuration
   ---------- --------------------------
   cat        CONFIG_NFILE_DESCRIPTORS > 0
+  cd         !CONFIG_DISABLE_ENVIRON && CONFIG_NFILE_DESCRIPTORS > 0
   cp         CONFIG_NFILE_DESCRIPTORS > 0
   echo       --
   exec       --
@@ -51,6 +52,7 @@ examples/nsh
   mkfifo     !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0
   mount      !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_FAT
   ps         --
+  pwd        !CONFIG_DISABLE_ENVIRON && CONFIG_NFILE_DESCRIPTORS > 0
   set        !CONFIG_DISABLE_ENVIRON
   sleep      !CONFIG_DISABLE_SIGNALS
   sh         CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NFILE_STREAMS > 0

examples/nsh/nsh.h

@@ -100,6 +100,12 @@
 #undef CONFIG_EXAMPLES_NSH_TELNETD_DUMPBUFFER
 #undef CONFIG_EXAMPLES_NSH_FULLPATH
 
+/* Make sure that the home directory is defined */
+
+#ifndef CONFIG_LIB_HOMEDIR
+# define CONFIG_LIB_HOMEDIR "/"
+#endif
+
 #define nsh_clone(v)           (v)->clone(v)
 #define nsh_addref(v)          (v)->addref(v)
 #define nsh_release(v)         (v)->release(v)
@@ -116,6 +122,13 @@
 
 #define SAVE_SIZE (sizeof(int) + sizeof(FILE*) + sizeof(boolean))
 
+/* Stubs used when working directory is not supported */
+
+#if CONFIG_NFILE_DESCRIPTORS <= 0 || defined(CONFIG_DISABLE_ENVIRON)
+#  define nsh_getfullpath(v,p) (p)
+#  define nsh_freefullpath(p)
+#endif
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/
@@ -211,6 +224,14 @@ extern int nsh_consolemain(int argc, char *argv[]);
 extern int nsh_telnetmain(int argc, char *argv[]);
 #endif
 
+/* Working directory support */
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+extern FAR const char *nsh_getcwd(void);
+extern char *nsh_getfullpath(FAR struct nsh_vtbl_s *vtbl, const char *relpath);
+extern void nsh_freefullpath(char *relpath);
+#endif
+
 /* Shell command handlers */
 
 extern int cmd_echo(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
@@ -238,6 +259,10 @@ extern int cmd_ps(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
       extern int cmd_umount(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
 #   endif /* CONFIG_FS_FAT */
 # endif /* !CONFIG_DISABLE_MOUNTPOINT */
+# if !defined(CONFIG_DISABLE_ENVIRON)
+  extern int cmd_cd(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
+  extern int cmd_pwd(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
+# endif /* !CONFIG_DISABLE_MOUNTPOINT */
 #endif /* CONFIG_NFILE_DESCRIPTORS */
 
 #if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0

examples/nsh/nsh_envcmds.c

@@ -42,7 +42,9 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <string.h>
+#include <libgen.h>
 #include <errno.h>
 
 #include "nsh.h"
@@ -63,6 +65,12 @@
  * Private Data
  ****************************************************************************/
 
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+static const char g_pwd[]    = "PWD";
+static const char g_oldpwd[] = "OLDPWD";
+static const char g_home[]   = CONFIG_LIB_HOMEDIR;
+#endif
+
 /****************************************************************************
  * Public Data
  ****************************************************************************/
@@ -71,10 +79,188 @@
  * Private Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: nsh_getwd
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+static inline FAR const char *nsh_getwd(const char *wd)
+{
+  const char *val;
+
+  /* If no working directory is defined, then default to the home directory */
+
+  val = getenv(wd);
+  if (!val)
+    {
+      val = g_home;
+    }
+  return val;
+}
+#endif
+
+/****************************************************************************
+ * Name: nsh_getdirpath
+ ****************************************************************************/
+
+static inline char *nsh_getdirpath(FAR struct nsh_vtbl_s *vtbl,
+                                   const char *dirpath, const char *relpath)
+{
+  char *alloc;
+  int len;
+
+  /* Handle the special case where the dirpath is simply  */
+
+  if (strcmp(dirpath, "/") == 0)
+    {
+      len   = strlen(relpath) + 2;
+      alloc = (char*)malloc(len);
+      if (alloc)
+        {
+          sprintf(alloc, "/%s", relpath);
+        }
+    }
+  else
+    {
+      len = strlen(dirpath) + strlen(relpath) + 2;
+      alloc = (char*)malloc(len);
+      if (alloc)
+        {
+          sprintf(alloc, "%s/%s", dirpath, relpath);
+        }
+    }
+
+  if (!alloc)
+    {
+      nsh_output(vtbl, g_fmtcmdoutofmemory, "nsh_getdirpath");
+    }
+  return alloc;
+}
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: nsh_getwd
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+FAR const char *nsh_getcwd(void)
+{
+  return nsh_getwd(g_pwd);
+}
+#endif
+/****************************************************************************
+ * Name: nsh_getfullpath
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+char *nsh_getfullpath(FAR struct nsh_vtbl_s *vtbl, const char *relpath)
+{
+  const char *wd;
+
+  /* Handle some special cases */
+
+  if (!relpath || relpath[0] == '\0')
+    {
+      /* No relative path provided */
+
+      return strdup(g_home);
+    }
+  else if (relpath[0] == '/')
+    {
+      return strdup(relpath);
+    }
+
+  /* Get the path to the current working directory */
+   
+  wd = nsh_getcwd();
+
+  /* Fake the '.' directory */
+
+  if (strcmp(relpath, ".") == 0)
+    {
+      return strdup(wd);
+    }
+
+  /* Return the full path */
+
+  return nsh_getdirpath(vtbl, wd, relpath);
+}
+#endif
+
+/****************************************************************************
+ * Name: nsh_freefullpath
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+void nsh_freefullpath(char *relpath)
+{
+  if (relpath)
+    {
+      free(relpath);
+    }
+}
+#endif
+
+/****************************************************************************
+ * Name: cmd_cd
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+int cmd_cd(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
+{
+  const char *path = argv[1];
+  char *alloc = NULL;
+  char *fullpath = NULL;
+  int ret = OK;
+
+  /* Check for special arguments */
+
+  if (argc < 2 || strcmp(path, "~") == 0)
+    {
+      path = g_home;
+    }
+  else if (strcmp(path, "-") == 0)
+    {
+      alloc = strdup(nsh_getwd(g_oldpwd));
+      path  = alloc;
+    }
+  else if (strcmp(path, "..") == 0)
+    {
+      alloc = strdup(nsh_getcwd());
+      path  = dirname(alloc);
+    }
+  else
+    {
+      fullpath = nsh_getfullpath(vtbl, path);
+      path     = fullpath;
+    }
+
+  /* Set the new workding directory */
+
+  if (chdir(path) != 0)
+    {
+      nsh_output(vtbl, g_fmtcmdfailed, argv[0], "chdir", NSH_ERRNO);
+      ret = ERROR;
+    }
+
+  /* Free any memory that was allocated */
+
+  if (alloc)
+    {
+      free(alloc);
+    }
+
+  if (fullpath)
+    {
+      nsh_freefullpath(fullpath);
+    }
+  return ret;
+}
+#endif
+
 /****************************************************************************
  * Name: cmd_echo
  ****************************************************************************/
@@ -95,6 +281,18 @@ int cmd_echo(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
   return OK;
 }
 
+/****************************************************************************
+ * Name: cmd_pwd
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+int cmd_pwd(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
+{
+  nsh_output(vtbl, "%s\n", nsh_getcwd());
+  return OK;
+}
+#endif
+
 /****************************************************************************
  * Name: cmd_set
  ****************************************************************************/

examples/nsh/nsh_main.c

@@ -91,6 +91,9 @@ static const struct cmdmap_s g_cmdmap[] =
 {
 #if CONFIG_NFILE_DESCRIPTORS > 0
   { "cat",      cmd_cat,      2, NSH_MAX_ARGUMENTS, "<path> [<path> [<path> ...]]" },
+#ifndef CONFIG_DISABLE_ENVIRON
+  { "cd",       cmd_cd,       1, 2, "[<dir-path>|-|~|..]" },
+#endif
   { "cp",       cmd_cp,       3, 3, "<source-path> <dest-path>" },
 #endif
 #ifndef CONFIG_DISABLE_ENVIRON
@@ -105,7 +108,7 @@ static const struct cmdmap_s g_cmdmap[] =
   { "ifconfig", cmd_ifconfig, 1, 1, NULL },
 #endif
 #if CONFIG_NFILE_DESCRIPTORS > 0
-  { "ls",       cmd_ls,       2, 5, "[-lRs] <dir-path>" },
+  { "ls",       cmd_ls,       1, 5, "[-lRs] <dir-path>" },
 #endif
   { "mb",       cmd_mb,       2, 3, "<hex-address>[=<hex-value>][ <hex-byte-count>]" },
 #if !defined(CONFIG_DISABLE_MOUNTPOINT) && CONFIG_NFILE_DESCRIPTORS > 0
@@ -123,6 +126,9 @@ static const struct cmdmap_s g_cmdmap[] =
 #endif
   { "mw",       cmd_mw,       2, 3, "<hex-address>[=<hex-value>][ <hex-byte-count>]" },
   { "ps",       cmd_ps,       1, 1, NULL },
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_ENVIRON)
+  { "pwd",      cmd_pwd,      1, 1, NULL },
+#endif
 #ifndef CONFIG_DISABLE_ENVIRON
   { "set",      cmd_set,      3, 3, "<name> <value>" },
 #endif
@@ -132,7 +138,7 @@ static const struct cmdmap_s g_cmdmap[] =
 #endif
 #if  CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NFILE_STREAMS > 0
   { "sh",       cmd_sh,       2, 2, "<script-path>" },
-# endif  /* CONFIG_NFILE_STREAMS */
+#endif  /* CONFIG_NFILE_DESCRIPTORS && CONFIG_NFILE_STREAMS */
 #ifndef CONFIG_DISABLE_SIGNALS
   { "sleep",    cmd_sleep,    2, 2, "<sec>" },
 #endif /* CONFIG_DISABLE_SIGNALS */
@@ -847,7 +853,7 @@ int nsh_parse(FAR struct nsh_vtbl_s *vtbl, char *cmdline)
         {
           vtbl->np.np_redirect = TRUE;
           oflags               = O_WRONLY|O_CREAT|O_TRUNC;
-          redirfile            = argv[argc-1];
+          redirfile            = nsh_getfullpath(vtbl, argv[argc-1]);
           argc                -= 2;
         }
 
@@ -857,7 +863,7 @@ int nsh_parse(FAR struct nsh_vtbl_s *vtbl, char *cmdline)
         {
           vtbl->np.np_redirect = TRUE;
           oflags               = O_WRONLY|O_CREAT|O_APPEND;
-          redirfile            = argv[argc-1];
+          redirfile            = nsh_getfullpath(vtbl, argv[argc-1]);
           argc                -= 2;
         }
     }
@@ -873,6 +879,9 @@ int nsh_parse(FAR struct nsh_vtbl_s *vtbl, char *cmdline)
        */
 
       fd = open(redirfile, oflags, 0666);
+      nsh_freefullpath(redirfile);
+      redirfile = NULL;
+
       if (fd < 0)
         {
           nsh_output(vtbl, g_fmtcmdfailed, cmd, "open", NSH_ERRNO);

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
 

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;
+    }
 
-  duppath = strdup(path);
+  /* Something exists here... is it a directory? */
 
-  /* Free any preceding cwd and set the previous to the cwd (this
-   * is to support 'cd -' in NSH
+  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)
    */
 
-  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 */

lib/lib_cwdsem.c

@@ -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 */

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;
+  char *pwd;
 
-    /* Verify input parameters */
+  /* Verify input parameters */
 
-    if (!buf || !size)
-      {
-        err = EINVAL;
-        goto errout;
-      }
+  if (!buf || !size)
+    {
+      errno = EINVAL;
+      return NULL;
+    }
 
-    /* If no working directory is defined, then default to the home directory */
+  /* 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;
-      }
+  pwd = getenv("PWD");
+  if (!pwd)
+    {
+      pwd = CONFIG_LIB_HOMEDIR;
+    }
 
-    /* Verify that the cwd will fit into the user-provided buffer */
+  /* Verify that the cwd will fit into the user-provided buffer */
 
-    if (strlen(ptr) + 1 > size)
-      {
-        err = ERANGE;
-        goto errout_with_sem;
-      }
+  if (strlen(pwd) + 1 > size)
+    {
+      errno = ERANGE;
+      return NULL;
+    }
 
-   /* Copy the cwd to the user buffer */
+  /* Copy the cwd to the user buffer */
 
-   strcpy(buf, ptr);
-   cwd_semgive();
-   return buf;
-
-errout_with_sem:
-  cwd_semgive();
-errout:
-  errno = err;
-  return NULL;
+  strcpy(buf, pwd);
+  sched_unlock();
+  return buf;
 }
-#endif /* CONFIG_NFILE_DESCRIPTORS */
+#endif /* CONFIG_NFILE_DESCRIPTORS && !CONFIG_DISABLE_ENVIRON */

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 */