-/**
- * Safely print into a buffer at a given offset
- *
- * \param b Determines the buffer, its size, and the offset.
- * \param fmt The format string.
- *
- * This function prints into the buffer given by \a b at the offset which is
- * also given by \a b. If there is not enough space to hold the result, the
- * buffer size is doubled until the underlying call to vsnprintf() succeeds
- * or the size of the buffer exceeds the maximal size specified in \a pb.
- *
- * In the latter case the unmodified \a buf and \a offset values as well as the
- * private_data pointer of \a b are passed to the \a max_size_handler of \a b.
- * If this function succeeds, i.e. returns a non-negative value, the offset of
- * \a b is reset to zero and the given data is written to the beginning of the
- * buffer.
- *
- * Upon return, the offset of \a b is adjusted accordingly so that subsequent
- * calls to this function append data to what is already contained in the
- * buffer.
- *
- * It's OK to call this function with \p b->buf being \p NULL. In this case, an
- * initial buffer is allocated.
- *
- * \return The number of bytes printed into the buffer (not including the
- * therminating \p NULL byte).
- *
- * \sa make_message(), vsnprintf(3).
- */
-__printf_2_3 int para_printf(struct para_buffer *b, const char *fmt, ...)