Merge remote-tracking branch 'origin/master' into bas24

ChangeLog

@@ -8904,5 +8904,9 @@
 	  (2014-10-29).
 	* configs/efm32gg-stk3700:  Board support for the SiLbas EFM32GG
 	  Giant Gecko Starter kit.  Current with basic NSH configuration only.
-	  Testing is on hold until I receive hardware (20145-11-03).
+	  Testing is on hold until I receive hardware (2014-11-03).
-
+	* libc/Kconfig: Move CONFIG_NSH_TMPDIR to CONFIG_LIBC_TMPDIR (2014-11-05).
+	* libc/stdlib/lib_mkstemp.c, lib_mktemp.c, Make.defs and include/stdlib.h:
+	  Add mktemp() and mkstemp() (2014-11-05).
+	* libc/stdio/lib_tempnam.c, lib_tmpnam.c, Kconfig, Make.defs and
+	  include/stdio.h: Add tmpnam() and tempnam() (2014-11-05).

Documentation/NuttxUserGuide.html

@@ -13,7 +13,7 @@
       <h1><big><font color="#3c34ec"><i>NuttX Operating System<p>User's Manual</i></font></big></h1>
       <p><small>by</small></p>
       <p>Gregory Nutt<p>
-      <p>Last Updated: October 4, 2014</p>
+      <p>Last Updated: November 5, 2014</p>
     </td>
   </tr>
 </table>
@@ -7629,11 +7629,12 @@ interface of the same name.
   <li><a href="#directoryoperations">2.10.3 Directory Operations</a></li>
   <li><a href="#dirunistdops">2.10.4 UNIX Standard Operations</a></li>
   <li><a href="#standardio">2.10.5 Standard I/O</a></li>
-  <li><a href="#aio">2.10.6 Asynchronous I/O</a></li>
+  <li><a href="#standardlib">2.10.6 Standard Library</a></li>
-  <li><a href="#stdstrings">2.10.7 Standard String Operations</a></li>
+  <li><a href="#aio">2.10.7 Asynchronous I/O</a></li>
-  <li><a href="#PipesNFifos">2.10.8 Pipes and FIFOs</a></li>
+  <li><a href="#stdstrings">2.10.8 Standard String Operations</a></li>
-  <li><a href="#fatsupport">2.10.9 FAT File System Support</a></li>
+  <li><a href="#PipesNFifos">2.10.9 Pipes and FIFOs</a></li>
-  <li><a href="#mmapxip">2.10.10 <code>mmap()</code> and eXecute In Place (XIP)</a></li>
+  <li><a href="#fatsupport">2.10.10 FAT File System Support</a></li>
+  <li><a href="#mmapxip">2.10.11 <code>mmap()</code> and eXecute In Place (XIP)</a></li>
 </ul>
 
 <h3><a name="FileSystemOverview">2.10.1 NuttX File System Overview</a></h3>
@@ -7953,6 +7954,8 @@ int    dprintf(int fd, FAR const char *fmt, ...);
 int    vdprintf(int fd, FAR const char *fmt, va_list ap);
 
 int    statfs(FAR const char *path, FAR struct statfs *buf);
+FAR char *tmpnam(FAR char *s);
+FAR char *tempnam(FAR const char *dir, FAR const char *pfx);
 
 #include &lt;sys/stat.h&gt;
 
@@ -7967,7 +7970,19 @@ int statfs(const char *path, struct statfs *buf);
 int fstatfs(int fd, struct statfs *buf);
 </pre></ul>
 
-<h3><a name="aio">2.10.6 Asynchronous I/O</a></h3>
+<h3><a name="standardlib">2.10.6 Standard Library</a></h3>
+<p>
+  <code>stdlib.h</code> generally addresses other operating system interfaces.
+  However, the following may also be considered as file system interfaces:
+</p>
+<ul><pre>
+#include &lt;stdlib.h&gt;
+
+int mktemp(FAR char *template);
+int mkstemp(FAR char *template);
+</pre></ul>
+
+<h3><a name="aio">2.10.7 Asynchronous I/O</a></h3>
 <ul><pre>
 #include &lt;aio.h&gt;
 
@@ -7983,7 +7998,7 @@ int lio_listio(int mode, FAR struct aiocb *const list[], int nent,
                FAR struct sigevent *sig);
 </pre></ul>
 
-<h3><a name="stdstrings">2.10.7 Standard String Operations</a></h3>
+<h3><a name="stdstrings">2.10.8 Standard String Operations</a></h3>
 <ul><pre>
 #include &lt;string.h&gt;
 
@@ -8017,9 +8032,9 @@ void  *memmove(void *dest, const void *src, size_t count);
 # define bzero(s,n) (void)memset(s,0,n)
 </pre></ul>
 
-<h3><a name="PipesNFifos">2.10.8 Pipes and FIFOs</a></h3>
+<h3><a name="PipesNFifos">2.10.9 Pipes and FIFOs</a></h3>
 
-<h3>2.10.8.1 <a name="pipe"><code>pipe</code></a></h3>
+<h3>2.10.9.1 <a name="pipe"><code>pipe</code></a></h3>
 <p>
   <b>Function Prototype:</b>
 </p>
@@ -8053,7 +8068,7 @@ int pipe(int fd[2]);
   </ul>
 </p>
 
-<h3>2.10.8.2 <a name="mkfifo"><code>mkfifo</code></a></h3>
+<h3>2.10.9.2 <a name="mkfifo"><code>mkfifo</code></a></h3>
 <p>
   <b>Function Prototype:</b>
 </p>
@@ -8100,8 +8115,8 @@ int mkfifo(FAR const char *pathname, mode_t mode);
   </ul>
 </p>
 
-<h3><a name="fatsupport">2.10.9 FAT File System Support</a></h3>
+<h3><a name="fatsupport">2.10.10 FAT File System Support</a></h3>
-<h3>2.10.9.1 <a name="mkfatfs"><code>mkfatfs</code></a></h3>
+<h3>2.10.10.1 <a name="mkfatfs"><code>mkfatfs</code></a></h3>
 <p>
   <b>Function Prototype:</b>
 </p>
@@ -8178,7 +8193,7 @@ struct fat_format_s
   </ul>
 </p>
 
-<h3><a name="mmapxip">2.10.10 <code>mmap()</code> and eXecute In Place (XIP)</a></h3>
+<h3><a name="mmapxip">2.10.11 <code>mmap()</code> and eXecute In Place (XIP)</a></h3>
 <p>
   NuttX operates in a flat open address space and is focused on MCUs that do
   support Memory Management Units (MMUs).  Therefore, NuttX generally does not
@@ -8307,7 +8322,7 @@ struct fat_format_s
   </li>
 </ol>
 
-<h3><a name="mmap">2.10.10.1 <code>mmap</code></a></h3>
+<h3><a name="mmap">2.10.11.1 <code>mmap</code></a></h3>
 <p>
   <b>Function Prototype:</b>
 </p>

include/stdio.h

@@ -78,6 +78,26 @@
 #define getchar()  fgetc(stdin)
 #define rewind(s)  ((void)fseek((s),0,SEEK_SET))
 
+/* Path to the directory where temporary files can be created */
+
+#ifndef CONFIG_LIBC_TMPDIR
+#  define CONFIG_LIBC_TMPDIR "/tmp"
+#endif
+
+#define P_tmpdir CONFIG_LIBC_TMPDIR
+
+/* Maximum size of character array to hold tmpnam() output. */
+
+#ifndef CONFIG_LIBC_MAX_TMPFILE
+#  define CONFIG_LIBC_MAX_TMPFILE 32
+#endif
+
+#define L_tmpnam CONFIG_LIBC_MAX_TMPFILE
+
+/* the maximum number of unique temporary file names that can be generated */
+
+#define TMP_MAX 56800235584ull
+
 /****************************************************************************
  * Public Type Definitions
  ****************************************************************************/
@@ -161,6 +181,8 @@ int    vdprintf(int fd, FAR const char *fmt, va_list ap);
 /* Operations on paths */
 
 int    statfs(FAR const char *path, FAR struct statfs *buf);
+FAR char *tmpnam(FAR char *s);
+FAR char *tempnam(FAR const char *dir, FAR const char *pfx);
 
 #undef EXTERN
 #if defined(__cplusplus)

include/stdlib.h

@@ -1,7 +1,7 @@
 /****************************************************************************
  * include/stdlib.h
  *
- *   Copyright (C) 2007-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -182,6 +182,8 @@ long int labs(long int j);
 #ifdef CONFIG_HAVE_LONG_LONG
 long long int llabs(long long int j);
 #endif
+int      mktemp(FAR char *template);
+int      mkstemp(FAR char *template);
 
 /* Sorting */
 

libc/Kconfig

@@ -192,6 +192,27 @@ config LIBC_PERROR_STDOUT
 		be defined, however, to provide perror() output that is serialized with
 		other stdout messages.
 
+config LIBC_TMPDIR
+	string "Temporary file directory"
+	default "/tmp"
+	depends on FS_WRITABLE
+		---help---
+		If a write-able file system is selected, this string will be
+		provided to specify the full path to a directory where temporary
+		files can be created.  This would be a good application of RAM disk:
+		To provide temporary storage for application data.
+
+config LIBC_MAX_TMPFILE
+	int "Maximum size of a temporary file path"
+	default 32
+	depends on FS_WRITABLE
+		---help---
+		If a write-able file system is selected, then temporary file may be
+		supported at the path provided by LIBC_TMPDIR.  The tmpnam() interface
+		keeps a static copy of this last filename produced; this value is the
+		maximum size of that last filename.  This size is the size of the full
+		file path.
+
 config ARCH_LOWPUTC
 	bool "Low-level console output"
 	default "y"

libc/stdio/Make.defs

@@ -65,6 +65,10 @@ CSRCS += lib_vprintf.c lib_fprintf.c lib_vfprintf.c lib_stdinstream.c
 CSRCS += lib_stdoutstream.c lib_stdsistream.c lib_stdsostream.c lib_perror.c
 CSRCS += lib_feof.c lib_ferror.c lib_clearerr.c
 
+endif
+
+ifeq ($(CONFIG_FS_WRITABLE),y)
+CSRCS += lib_tempnam.c lib_tmpnam.c
 endif
 endif
 

libc/stdio/lib_tempnam.c

@@ -0,0 +1,105 @@
+/****************************************************************************
+ * libc/stdio/lib_tempnam.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: tempnam
+ *
+ * Description:
+ *   The tempnam() function generates a pathname that may be used for a
+ *   temporary file.
+ *
+ *   The tempnam() function allows the user to control the choice of a
+ *   directory. The dir argument points to the name of the directory in which
+ *   the file is to be created. If dir is a null pointer or points to a
+ *   string which is not a name for an appropriate directory, the path prefix
+ *   defined as P_tmpdir in the <stdio.h> header will be used. If that
+ *   directory is not accessible, an implementation-defined directory may be
+ *   used.
+ *
+ *   Many applications prefer their temporary files to have certain initial
+ *   letter sequences in their names. The pfx argument should be used for
+ *   this. This argument may be a null pointer or point to a string of up
+ *   to five bytes to be used as the beginning of the filename.
+ *
+ * Returned Value:
+ *   Upon successful completion, tempnam() will allocate space for a string
+ *   put the generated pathname in that space, and return a pointer to it.
+ *   The pointer will be suitable for use in a subsequent call to free().
+ *   Otherwise, it will return a null pointer and set errno to indicate the
+ *   error.
+ *
+ *   The tempnam() function will fail if:
+ *     ENOMEM - Insufficient storage space is available.
+ *
+ ****************************************************************************/
+
+FAR char *tempnam(FAR const char *dir, FAR const char *pfx)
+{
+  FAR char *path;
+  int ret;
+
+  (void)asprintf(&path, "%s/%s-XXXXXX.tmp", dir, pfx);
+  if (path)
+    {
+      ret = mktemp(path);
+      if (ret == OK)
+        {
+          return path;
+        }
+
+      free(path);
+    }
+
+  set_errno(ENOMEM);
+  return NULL;
+}

libc/stdio/lib_tmpnam.c

@@ -0,0 +1,95 @@
+/****************************************************************************
+ * libc/stdio/lib_tmpnam.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: tmpnam
+ *
+ * Description:
+ *   The tmpnam() function generates a string that is a valid filename and
+ *   that is not the same as the name of an existing file. The function is
+ *   potentially capable of generating TMP_MAX different strings, but any or
+ *   all of them may already be in use by existing files and thus not be
+ *   suitable return values.
+ *
+ *   The tmpnam() function generates a different string each time it is
+ *   called from the same process, up to {TMP_MAX} times. If it is called
+ *   more than {TMP_MAX} times, the behavior is implementation-defined.
+ *
+ * Returned Value:
+ *   Upon successful completion, tmpnam() returns a pointer to a string. I
+ *   no suitable string can be generated, the tmpnam() function will
+ *   return a null pointer.
+ *
+ *   If the argument s is a null pointer, tmpnam() will leave its result
+ *   in an internal static object and return a pointer to that object.
+ *   Subsequent calls to tmpnam() may modify the same object. If the
+ *   argument s is not a null pointer, it is presumed to point to an
+ *   array of at least L_tmpnam chars; tmpnam() will write its result in
+ *   that array and will return the argument as its value.
+ *
+ ****************************************************************************/
+
+FAR char *tmpnam(FAR char *s)
+{
+  static char path[L_tmpnam];
+  int ret;
+
+  if (s == NULL)
+    {
+      s = path;
+    }
+
+  (void)snprintf(s, L_tmpnam, "%s/XXXXXX.tmp", P_tmpdir);
+  ret = mktemp(s);
+  return (ret == OK) ? s : NULL;
+}

libc/stdlib/Make.defs

@@ -40,6 +40,10 @@ CSRCS += lib_llabs.c lib_rand.c lib_qsort.c
 CSRCS += lib_strtol.c lib_strtoll.c lib_strtoul.c lib_strtoull.c
 CSRCS += lib_strtod.c lib_checkbase.c
 
+ifeq ($(CONFIG_FS_WRITABLE),y)
+CSRCS += lib_mktemp.c lib_mkstemp.c
+endif
+
 # Add the stdlib directory to the build
 
 DEPPATH += --dep-path stdlib

libc/stdlib/lib_mkstemp.c

@@ -0,0 +1,297 @@
+/****************************************************************************
+ * libc/stdlib/lib_mkstemp.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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 <nuttx/compiler.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <semaphore.h>
+#include <errno.h>
+
+#ifdef CONFIG_FS_WRITABLE
+
+/****************************************************************************
+ * Pre-processor definitions
+ ****************************************************************************/
+
+ #ifndef CONFIG_LIBC_TMPDIR
+#  define CONFIG_LIBC_TMPDIR "/tmp"
+#endif
+
+#define MAX_XS        6
+#define MIN_NUMERIC   0    /* 0-9:   Numeric */
+#define MAX_NUMERIC   9
+#define MIN_UPPERCASE 10   /* 10-35: Upper case */ 
+#define MAX_UPPERCASE 35
+#define MIN_LOWERCASE 36   /* 36-61: Lower case */
+#define MAX_LOWERCASE 61
+#define MAX_BASE62    MAX_LOWERCASE
+
+/* 62**1 = 62
+ * 62**2 = 3844
+ * 62**3 = 238328
+ * 62**4 = 14776336
+ * 62**5 = 916132832
+ * 62**6 = 56800235584 > UINT32_MAX
+ */
+
+#define BIG_XS 5
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static uint8_t g_base62[MAX_XS];
+static sem_t g_b62sem = SEM_INITIALIZER(1);
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: base62_to_char
+ *
+ * Description:
+ *   Convert a base62 value to a printable character.
+ *
+ ****************************************************************************/
+
+static char base62_to_char(uint8_t base62)
+{
+  if (base62 <= MAX_NUMERIC)
+    {
+      return '0' + base62;
+    }
+  else if (base62 <= MAX_UPPERCASE)
+    {
+      return 'A' + base62 - MIN_UPPERCASE;
+    }
+  else /* if (base62 <= MAX_LOWERCASE) */
+    {
+      DEBUGASSERT(base62 <= MAX_LOWERCASE);
+      return 'a' + base62 - MIN_LOWERCASE;
+    }
+}
+
+/****************************************************************************
+ * Name: incr_base62
+ *
+ * Description:
+ *   increment the base62 value array.
+ *
+ ****************************************************************************/
+
+static void incr_base62(void)
+{
+  int i;
+
+  for (i = 0; i < MAX_XS; i++)
+    {
+      if (g_base62[i] < MAX_LOWERCASE)
+        {
+          g_base62[i]++;
+          return;
+        }
+      else
+        {
+          g_base62[i] = 0;
+        }
+    }
+}
+
+/****************************************************************************
+ * Name: get_base62
+ *
+ * Description:
+ *   Atomically copy and increment the base62 array.
+ *
+ ****************************************************************************/
+
+static void get_base62(FAR uint8_t *ptr)
+{
+  int ret;
+
+  while ((ret = sem_wait(&g_b62sem)) < 0)
+    {
+      DEBUGASSERT(errno == EINTR);
+    }
+     
+  memcpy(ptr, g_base62, MAX_XS);
+  incr_base62();
+  sem_post(&g_b62sem);
+}
+
+/****************************************************************************
+ * Name: copy_base62
+ *
+ * Description:
+ *   Copy the base62 array into the template filename, converting each
+ *   base62 value to a printable character.
+ *
+ ****************************************************************************/
+
+static void copy_base62(FAR char *dest, int len)
+{
+  FAR const uint8_t *src;
+
+  src = g_base62;
+  if (len < MAX_XS)
+     {
+       src += MAX_XS - len;
+     }
+
+   for (; len > 0; len--)
+     {
+       *dest++ = base62_to_char(*src++);
+     }
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mkstemp
+ *
+ * Description:
+ *   The mkstemp() function replaces the contents of the string pointed to
+ *   by template by a unique filename, and returns a file descriptor for the
+ *   file open for reading and writing. The function thus prevents any
+ *   possible race condition between testing whether the file exists and
+ *   opening it for use. The string in template should look like a filename
+ *   with six trailing 'X' s; mkstemp() replaces each 'X' with a character
+ *   from the portable filename character set. The characters are chosen
+ *   such that the resulting name does not duplicate the name of an existing
+ *   file at the time of a call to mkstemp().
+ *
+ * Input Parameters:
+ *   template - The base file name that will be modified to produce the
+ *     unique file name.  This must be a full path beginning with /tmp.
+ *     This function will modify only the first XXXXXX characters within
+ *     that full path.
+ *
+ * Returned Value:
+ *
+ * Upon successful completion, mkstemp() returns an open file descriptor.
+ * Otherwise, -1 is returned if no suitable file could be created.
+ *
+ ****************************************************************************/
+
+int mkstemp(FAR char *template)
+{
+  uint8_t base62[MAX_XS];
+  uint32_t retries;
+  FAR char *xptr;
+  FAR char *ptr;
+  int xlen;
+  int fd;
+  int i;
+
+  /* Count the number of X's at the end of the template */
+
+  xptr = strchr(template, 'X');
+  if (!xptr)
+    {
+      /* No Xs?  There should always really be 6 */
+
+      return open(template, O_RDWR | O_CREAT | O_EXCL, 0666);
+    }
+
+  /* There is at least one.. count all of them */
+
+  for (xlen = 0, ptr = xptr; xlen < MAX_XS && *ptr == 'X'; xlen++, ptr++);
+
+  /* Ignore any X's after the sixth */
+
+  if (xlen > MAX_XS)
+    {
+      xlen = MAX_XS;
+    }
+
+  /* If xlen is small, then we need to determine the maximum number of
+   * retries before the values will repeat.
+   */
+
+  if (xlen >= BIG_XS)
+    {
+      retries = UINT32_MAX;
+    }
+  else
+    {
+      for (i = 1, retries = 62; i < xlen; i++, retries *= 62);
+    }
+
+  /* Then loop until we find a unique file name */
+
+  while (retries > 0)
+    {
+      /* Sample and increment the base62 counter */
+
+       get_base62(base62);
+
+      /* Form the candidate file name */
+
+      copy_base62(xptr, xlen);
+
+      /* Attempt to open the candidate file -- creating it exclusively
+       *
+       * REVISIT: This prohibits the use of this function to create unique
+       * directories
+       */
+
+      fd = open(template, O_RDWR | O_CREAT | O_EXCL, 0666);
+      if (fd >= 0)
+        {
+          /* We have it... return the file descriptor */
+
+          return fd;
+        }
+    }
+
+  /* We could not find an unique filename */
+
+  return ERROR;
+}
+
+#endif /* CONFIG_FS_WRITABLE */
+

libc/stdlib/lib_mktemp.c

@@ -0,0 +1,81 @@
+/****************************************************************************
+ * libc/stdlib/lib_mktemp.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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 <nuttx/compiler.h>
+
+#include <unistd.h>
+#include <stdlib.h>
+
+#ifdef CONFIG_FS_WRITABLE
+
+/****************************************************************************
+ * Pre-processor definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mktemp
+ *
+ * Description:
+ *   The use of mktemp is dangerous; use mkstemp instead.
+ *
+ ****************************************************************************/
+
+int mktemp(FAR char *template)
+{
+  int fd = mkstemp(template);
+  if (fd < 0)
+    {
+      return ERROR;
+    }
+
+  close(fd);
+  return OK;
+}
+
+#endif /* CONFIG_FS_WRITABLE */
+