Re: asynchronous process management on WinWP; buffering problem?

[Lennart Borgman <lennart.borgman.073@student.lu.se>]

I do not understand this so I have some (perhaps stupid) questions:

- What determines how the buffering works?
- Can a program like Emacs change this behaviour?
- When does the buffering works differently? In a "console"? Is cmd.exe 
a "console"? But is it not just another program?


kgold wrote:
> The output buffering is a common problem.  For C and perhaps other 
> languages, stdout is normally line buffered.  But when you pipe the 
> output (like through emacs) it becomes fully buffered.  So you don't 
> see the output until the buffer is full.
>
> I don't know if there's a general solution.  If it's C and you have 
> the source, this will fix it.
>
>     setvbuf(stdout, _IONBF, 0);
>
> Peter Tury wrote:
>> I try to control program xxx on MS WinXP from EmacsW32 (cvs). xxx 
>> runs in
>> DOS window normally and after a command it reads from stdin (until
>> newline), handles the input and, after another command, writes result to
>> stdout.
>>
>> However it seems that some buffering (in Emacs? in MS Windows'
>> stdin/stdout?) tries to kill me: I can't see the results (from 
>> stdout) in
>> the associated buffer, only if it is long enough. At least it seems 
>> so: if
>> I send many "\n"-s (to "generate" a lot of prompts (to fill up the
>> buffer?)) then I get everything together after a while (of course, if 
>> I run
>> the program normally (=in a DOS window) everything works fine)... I 
>> hope I
>> could handle this through filter functions, but...