Add chdir() and getcwd()

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@837 42af7a65-404d-4744-a932-0658087f49c3

6 files changed, 395 insertions, 29 deletions

diff --git a/nuttx/lib/Makefile b/nuttx/lib/Makefile
index 4f0eddb7a..cf35a0541 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 ($(CONFIG_NFILE_DESCRIPTORS),0)
-STDIO_SRCS	+= lib_rawstream.c
+STDIO_SRCS	+= lib_rawstream.c lib_chdir.c lib_getcwd.c lib_cwdsem.c
 ifneq ($(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 \
diff --git a/nuttx/lib/lib_chdir.c b/nuttx/lib/lib_chdir.c
new file mode 100644
index 000000000..008e923ec
--- /dev/null
+++ b/nuttx/lib/lib_chdir.c
@@ -0,0 +1,131 @@
+/****************************************************************************
+ * lib/lib_chdir.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 <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "lib_internal.h"
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0
+char *g_cwd     = NULL;
+char *g_prevcwd = NULL;
+
+/****************************************************************************
+ * 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)
+{
+  char *duppath;
+
+  /* Verify the input parameters */
+
+  if (!path)
+    {
+      errno = ENOENT;
+      return ERROR;
+    }
+
+  /* Verify that 'path' refers to a directory */
+  /* (To be provided) */
+
+  /* Make a persistent copy of 'path' */
+
+  duppath = strdup(path);
+
+  /* Free any preceding cwd and set the previous to the cwd (this
+   * is to support 'cd -' in NSH
+   */
+
+  cwd_semtake();
+  if (g_prevcwd)
+    {
+      free(g_prevcwd);
+    }
+  g_prevcwd = g_cwd;
+
+  /* Set the cwd to a persistent copy of the input 'path' */
+
+  g_cwd = duppath;
+  cwd_semgive();
+  return OK;
+}
+#endif /* CONFIG_NFILE_DESCRIPTORS */
diff --git a/nuttx/lib/lib_cwdsem.c b/nuttx/lib/lib_cwdsem.c
new file mode 100644
index 000000000..d06487890
--- /dev/null
+++ b/nuttx/lib/lib_cwdsem.c
@@ -0,0 +1,86 @@
+/****************************************************************************
+ * 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
new file mode 100644
index 000000000..a0db05c09
--- /dev/null
+++ b/nuttx/lib/lib_getcwd.c
@@ -0,0 +1,139 @@
+/****************************************************************************
+ * lib/lib_getcwd.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 <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "lib_internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getwcd
+ *
+ * Description:
+ *   getcwd() function places the absolute pathname of the current working
+ *   directory in the array pointed to by 'buf', and returns 'buf.' The
+ *   pathname copied to the array shall contain no components that are
+ *   symbolic links. The 'size' argument is the size in bytes of the
+ *   character array pointed to by the 'buf' argument.
+ *
+ * Input Parmeters:
+ *   buf - a pointer to the location in which the current working directory
+ *     pathaname is returned.
+ *   size - The size in bytes avaiable at 'buf'
+ *
+ * Returned Value:
+ *   Upon successful completion, getcwd() returns the 'buf' argument.
+ *   Otherwise, getcwd() returns a null pointer and sets errno to indicate
+ *   the error:
+ *
+ *   EINVAL
+ *     The 'size' argument is 0 or the 'buf' argument is NULL.
+ *   ERANGE
+ *     The size argument is greater than 0, but is smaller than the length
+ *     of the currrent working directory pathname +1.
+ *   EACCES
+ *     Read or search permission was denied for a component of the pathname.
+ *   ENOMEM
+ *  Insufficient storage space is available. 
+ *
+ ****************************************************************************/
+
+#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;
+}
+#endif /* CONFIG_NFILE_DESCRIPTORS */
diff --git a/nuttx/lib/lib_internal.h b/nuttx/lib/lib_internal.h
index 95dca3de8..067b64c24 100644
--- a/nuttx/lib/lib_internal.h
+++ b/nuttx/lib/lib_internal.h
@@ -1,7 +1,7 @@
-/************************************************************
- * lib_internal.h
+/****************************************************************************
+ * lib/lib_internal.h
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the
  *    distribution.
- * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ * 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.
  *
@@ -31,22 +31,26 @@
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  *
- ************************************************************/
+ ****************************************************************************/
 
 #ifndef __LIB_INTERNAL_H
 #define __LIB_INTERNAL_H
 
-/************************************************************
+/****************************************************************************
  * Included Files
- ************************************************************/
+ ****************************************************************************/
 
 #include <nuttx/config.h>
 #include <stdio.h>
 #include <semaphore.h>
 
-/************************************************************
+/****************************************************************************
  * Definitions
- ************************************************************/
+ ****************************************************************************/
+
+#ifndef CONFIG_LIB_HOMEDIR
+# define CONFIG_LIB_HOMEDIR "/"
+#endif
 
 #if CONFIG_STDIO_BUFFER_SIZE <= 0
 # define lib_sem_initialize(s)
@@ -56,9 +60,9 @@
 
 #define LIB_BUFLEN_UNKNOWN (0x7fffffff)
 
-/************************************************************
+/****************************************************************************
  * Public Types
- ************************************************************/
+ ****************************************************************************/
 
 /* This is the generic for of a stream used by the library
  * to manage variable sized output.
@@ -94,13 +98,18 @@ struct lib_rawstream_s
   int                  fd;
 };
 
-/************************************************************
+/****************************************************************************
  * 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
- ************************************************************/
+ ****************************************************************************/
 
 /* Defined in lib_streamsem.c */
 
@@ -184,4 +193,9 @@ 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 */
diff --git a/nuttx/lib/lib_strlen.c b/nuttx/lib/lib_strlen.c
index f2cf6f227..9c829c61f 100644
--- a/nuttx/lib/lib_strlen.c
+++ b/nuttx/lib/lib_strlen.c
@@ -1,7 +1,7 @@
-/************************************************************
- * lib_strlen.c
+/****************************************************************************
+ * lib/lib_strlen.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the
  *    distribution.
- * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ * 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.
  *
@@ -31,23 +31,19 @@
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  *
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Compilation Switches
- ************************************************************/
-
-/************************************************************
+/****************************************************************************
  * Included Files
- ************************************************************/
+ ****************************************************************************/
 
 #include <nuttx/config.h>
 #include <sys/types.h>
 #include <string.h>
 
-/************************************************************
+/****************************************************************************
  * Global Functions
- ************************************************************/
+ ****************************************************************************/
 
 #ifndef CONFIG_ARCH_STRLEN
 size_t strlen(const char *s)