[Flex-help] Reading from a buffer.

[Timothy S. Ph.D. <sch...@gm...>]

Hello,

I am using flex to scan a buffer I have in memory.  I see the methods 
yy_scan_string, yy_scan_bytes and yy_scan_buffer.  These methods appear 
to (1) copy data and (2) want to see two trailing NULLs at the end of 
the buffer.

So my question is: is there a way to have flex use an existing in-memory 
buffer that doesn't necessarily have two trailing NULLs without making 
an entire copy of it?  For example, can I just define the YY_INPUT macro 
to read from my buffer or something similar?

As a follow up, what is the motivation for requiring the trailing NULLs? 
  If you know the length why does it matter that a buffer has these?  I 
could make my own yy_scan_bytes method but I am worried that flex will 
not find the trailing NULLs it wants and everything will crash and burn.

Thanks!
Tim