yading@10: /*
yading@10:  * C99-compatible snprintf() and vsnprintf() implementations
yading@10:  * Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #include <stdio.h>
yading@10: #include <stdarg.h>
yading@10: #include <limits.h>
yading@10: #include <string.h>
yading@10: 
yading@10: #include "compat/va_copy.h"
yading@10: #include "libavutil/error.h"
yading@10: 
yading@10: #if defined(__MINGW32__)
yading@10: #define EOVERFLOW EFBIG
yading@10: #endif
yading@10: 
yading@10: int avpriv_snprintf(char *s, size_t n, const char *fmt, ...)
yading@10: {
yading@10:     va_list ap;
yading@10:     int ret;
yading@10: 
yading@10:     va_start(ap, fmt);
yading@10:     ret = avpriv_vsnprintf(s, n, fmt, ap);
yading@10:     va_end(ap);
yading@10: 
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: int avpriv_vsnprintf(char *s, size_t n, const char *fmt,
yading@10:                      va_list ap)
yading@10: {
yading@10:     int ret;
yading@10:     va_list ap_copy;
yading@10: 
yading@10:     if (n == 0)
yading@10:         return _vscprintf(fmt, ap);
yading@10:     else if (n > INT_MAX)
yading@10:         return AVERROR(EOVERFLOW);
yading@10: 
yading@10:     /* we use n - 1 here because if the buffer is not big enough, the MS
yading@10:      * runtime libraries don't add a terminating zero at the end. MSDN
yading@10:      * recommends to provide _snprintf/_vsnprintf() a buffer size that
yading@10:      * is one less than the actual buffer, and zero it before calling
yading@10:      * _snprintf/_vsnprintf() to workaround this problem.
yading@10:      * See http://msdn.microsoft.com/en-us/library/1kt27hek(v=vs.80).aspx */
yading@10:     memset(s, 0, n);
yading@10:     va_copy(ap_copy, ap);
yading@10:     ret = _vsnprintf(s, n - 1, fmt, ap_copy);
yading@10:     va_end(ap_copy);
yading@10:     if (ret == -1)
yading@10:         ret = _vscprintf(fmt, ap);
yading@10: 
yading@10:     return ret;
yading@10: }