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Diffstat (limited to 'nuttx/lib/stdio/lib_avsprintf.c')
-rw-r--r-- | nuttx/lib/stdio/lib_avsprintf.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/nuttx/lib/stdio/lib_avsprintf.c b/nuttx/lib/stdio/lib_avsprintf.c new file mode 100644 index 000000000..8561b97c2 --- /dev/null +++ b/nuttx/lib/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; +} |