size_t vrb_space_len(vrb_p vrb);
DESCRIPTIONvrb_space_len returns the total length of space available in the given virtual ring buffer. This is the maximum space the caller may store into the buffer from the pointer returned by vrb_space_ptr(3).
specifies the virtual ring buffer to obtain the length of available space in. If a NULL or invalid pointer is given, results are unpredictable and are likely to be disasterous.
The length of available space in the virtual ring buffer is returned.