/*
 * $Id: stdio_vsnprintf.c,v 1.8 2006-01-08 12:04:25 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Neither the name of Olaf Barthel nor the names of 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.
 */

#ifndef _STDLIB_NULL_POINTER_CHECK_H
#include "stdlib_null_pointer_check.h"
#endif /* _STDLIB_NULL_POINTER_CHECK_H */

/****************************************************************************/

#ifndef _STDIO_HEADERS_H
#include "stdio_headers.h"
#endif /* _STDIO_HEADERS_H */

/****************************************************************************/

/* The following is not part of the ISO 'C' (1994) standard. */

/****************************************************************************/

int
vsnprintf(char *buffer,size_t size,const char *format,va_list arg)
{
	struct iob string_iob;
	int result = EOF;
	char local_buffer[32];

	ENTER();

	SHOWPOINTER(buffer);
	SHOWVALUE(size);
	SHOWSTRING(format);
	SHOWPOINTER(arg);

	assert( format != NULL && arg != NULL && (int)size >= 0 );

	if(__check_abort_enabled)
		__check_abort();

	#if defined(CHECK_FOR_NULL_POINTERS)
	{
		if(format == NULL || (buffer == NULL && size > 0))
		{
			SHOWMSG("invalid parameters");

			__set_errno(EFAULT);
			goto out;
		}
	}
	#endif /* CHECK_FOR_NULL_POINTERS */

	__initialize_iob(&string_iob,__vsnprintf_hook_entry,
		NULL,
		local_buffer,sizeof(local_buffer),
		-1,
		-1,
		IOBF_IN_USE | IOBF_WRITE | IOBF_NO_NUL | IOBF_BUFFER_MODE_NONE | IOBF_INTERNAL,
		NULL);

	/* Store up to 'size-1' characters in the output buffer. This
	   does not include the terminating NUL character, which we
	   will add later. */
	string_iob.iob_String		= (STRPTR)buffer;
	string_iob.iob_StringSize	= (size > 0) ? (size - 1) : 0;

	/* We will return the number of characters that would have been
	   stored if there had been enough room. */
	result = vfprintf((FILE *)&string_iob,format,arg);

	/* Figure out how many characters were stored. Fewer than
	   the output buffer size allows for may have been written
	   to the buffer. The string needs to be terminated with a
	   NUL byte behind the last character stored. */
	if(size > 0)
	{
		assert( string_iob.iob_StringPosition >= 0 );
		assert( string_iob.iob_StringPosition+1 <= size );

		buffer[string_iob.iob_StringPosition] = '\0';

		SHOWSTRING(buffer);
	}
	else
	{
		SHOWMSG("output buffer is empty");
	}

 out:

	RETURN(result);
	return(result);
}