1 files changed, 146 insertions, 0 deletions
diff --git a/nuttx/libc/stdio/lib_avsprintf.c b/nuttx/libc/stdio/lib_avsprintf.c
new file mode 100644
index 000000000..8561b97c2
--- /dev/null
+++ b/nuttx/libc/stdio/lib_avsprintf.c
@@ -0,0 +1,146 @@
+/****************************************************************************
+ * lib/stdio/lib_avsprintf.c
+ *
+ *   Copyright (C) 2011-2012 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 <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <assert.h>
+
+#include "lib_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: avsprintf
+ *
+ * Description:
+ *   This function is similar to vsprintf, except that it dynamically
+ *   allocates a string (as with malloc) to hold the output, instead of
+ *   putting the output in a buffer you allocate in advance.  The ptr
+ *   argument should be the address of a char * object, and a successful
+ *   call to avsprintf stores a pointer to the newly allocated string at that
+ *   location.
+ *
+ * Returned Value:
+ *   The returned value is the number of characters allocated for the buffer,
+ *   or less than zero if an error occurred. Usually this means that the buffer
+ *   could not be allocated.
+ *
+ ****************************************************************************/
+
+int avsprintf(FAR char **ptr, const char *fmt, va_list ap)
+{
+  struct lib_outstream_s nulloutstream;
+  struct lib_memoutstream_s memoutstream;
+  FAR char *buf;
+  int nbytes;
+
+  DEBUGASSERT(ptr && fmt);
+
+  /* First, use a nullstream to get the size of the buffer.  The number
+   * of bytes returned may or may not include the null terminator.
+   */
+  
+  lib_nulloutstream(&nulloutstream);
+  nbytes = lib_vsprintf((FAR struct lib_outstream_s *)&nulloutstream, fmt, ap);
+
+  /* Then allocate a buffer to hold that number of characters, adding one
+   * for the null terminator.
+   */
+
+  buf = (FAR char *)malloc(nulloutstream.nput + 1);
+  if (!buf)
+    {
+      return ERROR;
+    }
+
+  /* Initialize a memory stream to write into the allocated buffer.  The
+   * memory stream will reserve one byte at the end of the buffer for the
+   * null terminator and will not report this in the number of output bytes.
+   */
+
+  lib_memoutstream((FAR struct lib_memoutstream_s *)&memoutstream,
+                   buf, nulloutstream.nput + 1);
+
+  /* Then let lib_vsprintf do it's real thing */
+
+  nbytes = lib_vsprintf((FAR struct lib_outstream_s *)&memoutstream.public, fmt, ap);
+
+  /* Return a pointer to the string to the caller.  NOTE: the memstream put()
+   * method has already added the NUL terminator to the end of the string (not
+   * included in the nput count).
+   *
+   * Hmmm.. looks like the memory would be stranded if lib_vsprintf() returned
+   * an error.  Does that ever happen?
+   */
+
+  DEBUGASSERT(nbytes < 0 || nbytes == nulloutstream.nput);
+  *ptr = buf;
+  return nbytes;
+}