kolibrios-fun/programs/develop/open watcom/trunk/clib/string/sprntf_s.c

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/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: Implementation of sprintf_s() - safe formatted string output.
*
****************************************************************************/
#include "variety.h"
#include "saferlib.h"
#include "widechar.h"
#include <stdio.h>
#include <stdarg.h>
#include <wchar.h>
#include "printf.h"
/*
* mem_putc -- append a character to a string in memory, with overflow check
*/
struct vsprtf_s_buf {
CHAR_TYPE *bufptr;
rsize_t chars_output;
rsize_t max_chars;
};
static slib_callback_t mem_putc; // set up calling convention
static void __SLIB_CALLBACK mem_putc( SPECS __SLIB *specs, int op_char )
{
struct vsprtf_s_buf *info;
info = (struct vsprtf_s_buf *)specs->_dest;
if( info->chars_output <= info->max_chars ) {
*( info->bufptr++ ) = op_char;
specs->_output_count++;
info->chars_output++;
}
}
_WCRTLINK int __F_NAME(sprintf_s,swprintf_s)( CHAR_TYPE * __restrict s, rsize_t n,
const CHAR_TYPE * __restrict format, ... )
{
va_list arg;
struct vsprtf_s_buf info;
const char *msg;
int rc = 0;
/* First check the critical conditions; if any of those
* is violated, return immediately and don't touch anything.
*/
if( __check_constraint_nullptr_msg( msg, s )
&& __check_constraint_maxsize_msg( msg, n )
&& __check_constraint_zero_msg( msg, n ) ) {
/* The buffer looks okay, try doing something useful */
if( __check_constraint_nullptr_msg( msg, format ) ) {
info.bufptr = s;
info.chars_output = 0;
info.max_chars = n - 1;
msg = NULL;
va_start( arg, format );
__F_NAME(__prtf_s,__wprtf_s)( &info, format, arg, &msg, mem_putc );
va_end( arg );
if( msg == NULL ) {
if( info.chars_output <= info.max_chars ) {
s[info.chars_output] = NULLCHAR;
return( info.chars_output );
}
/* If we got here, the output buffer was too small */
msg = "n < chars_output";
#ifdef __WIDECHAR__
rc = -1; /* Return value for swprintf_s is different! */
#endif
}
}
/* Something went wrong, output buffer will contain empty string */
*s = NULLCHAR;
}
__rtct_fail( __func__, msg, NULL );
return( rc );
}