Line based buffers malfunctioning in Win32?

[Peter van Eerten]

Hi all,

 

This is probably a very stupid problem, but I'll ask anyway, sincerely hoping nobody gets offensed. For my GTK-server I am experimenting with communication to an external process using TCP. By default, a TCP socket in GNU Prolog is buffered in block mode, and after a block of data, an explicit "flush_output/1" is needed to send the contents of the buffer to the socket.

 

When I change the buffermode (with "set_stream_buffering/2") to line, it seems that GNU Prolog is not able to actually send away the data after a newline. For example:

 

socket('AF_INET', Socket),
socket_connect(Socket, 'AF_INET'(localhost, 50000), In, Out),

set_stream_buffering(Out, line),
write(Out, 'Hello there'), nl(Out),
read_token(In, _),

.....<more code>.....

 

The "Hello there" is never received by the other side. This works neither:

 

socket('AF_INET', Socket),
socket_connect(Socket, 'AF_INET'(localhost, 50000), In, Out),

set_stream_buffering(Out, line),
write(Out, 'Hello there\n'),
read_token(In, _),

.....<more code>.....

 

The strange thing is, when I put the incoming stream to line mode, and keep using "read_token/2", it works perfectly OK. I also have tried other versions of "write", like "writeq", "write_term", etc., but that did not help me out.

 

Probably I am doing something wrong? Or is this some kind of buggy behaviour (let's hope not)? I saw this problem when using GNU Prolog 1.2.16 with Windows2000 SP 1.

 

Thank you,

 

Peter.

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