Re: Unbuffered Keyboard I/O

["Theodore E. Dennison" <dennison@escmail.mmc.orl.com>]

amlombardi@vms4.sci.csupomona.edu wrote:
>
> I posted earlier about unbuffered keyboard io, well it works really well (i
> used the one at owens.ridgecrest.ca.us) but when the package initializes itself
> it must screw with the i/o channels some how because the PUT statement does not
> work but all the others like PUT_LINE and NE~W_LINE work... PUT actually will
> show up after a PUT_LINE or a NE~W_LINE or quitting the program... anyone have
> any ideas on how to fix this?  Thanx in advance

Actually, this is quite common behavior for PUT. On many systems, PUT
I/Os are buffered, and only PUT_LINEs and NEW_LINEs flush that buffer.

In many OS's (VMS for one) exitting a program automaticly flushes all
I/O buffers.

I know VAX Ada exihibts this behavior. There may be other Ada's that 
do it as well.

The solution to this in VMS is to either 
  - Use PUT_LINE or NEW_LINE when the text absolutely HAS to be
    displayed.
  - Use the SMG package instead of Text_IO
  - Use QIOs (YUUUUCK!)
  - Use the FORM parameter when you open the text file to get Text_IO
    to not buffer any writes (I hope you are an RMS expert!)

If you ARE using VAX Ada, I suggest SMG.

T.E.D.