comparison ffmpeg/compat/msvcrt/snprintf.c @ 10:6840f77b83aa

commit

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