adtools/clib2

/*
 * $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);
}