@@ -73,4 +73,18 @@ size_t av_strlcpy(char *dst, const char *src, size_t size);

  */

 size_t av_strlcat(char *dst, const char *src, size_t size);

+/**

+ * Append output to a string, according to a format. Never write out of

+ * the destination buffer, and and always put a terminating 0 within

+ * the buffer.

+ * @param dst destination buffer (string to which the output is

+ *  appended)

+ * @param size total size of the destination buffer

+ * @param fmt printf-compatible format string, specifying how the

+ *  following parameters are used

+ * @return the length of the string that would have been generated

+ *  if enough space had been available

+ */

+size_t av_strlcatf(char *dst, size_t size, const char *fmt, ...);

+

 #endif /* AVUTIL_STRING_H */

@@ -19,6 +19,8 @@

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */

+#include <stdarg.h>

+#include <stdio.h>

 #include <string.h>

 #include <ctype.h>

 #include "avstring.h"

@@ -62,3 +64,15 @@ size_t av_strlcat(char *dst, const char *src, size_t size)

         return len + strlen(src);

     return len + av_strlcpy(dst + len, src, size - len);

 }

+

+size_t av_strlcatf(char *dst, size_t size, const char *fmt, ...)

+{

+    int len = strlen(dst);

+    va_list vl;

+

+    va_start(vl, fmt);

+    len += vsnprintf(dst + len, size > len ? size - len : 0, fmt, vl);

+    va_end(vl);

+

+    return len;

+}