Re: console vs pty (was: Re: First Pass at mintty documentation; etc.)

[Christopher Faylor <cgf-use-the-mailinglist-please@cygwin.com>]

On Thu, Jan 15, 2009 at 05:44:09AM +0000, Andy Koppe wrote:
>Chuck Wilson wrote:
>>"full screen" or "DOS" is a red herring.  Any program that does
>>something like the following, if compiled as a native program, won't
>>work in rxvt (or MinTTY, or cygwin/cmd-shell-with-CYGWIN=tty):
>>
>> #include <stdio.h>
>> main() {
>>   int c;
>>   while ((c = getc(stdin)) != EOF) fputc(c, stdout);
>> }
>>
>>The thing is, THIS program works as part of a pipeline even when
>>compiled as a native program -- but it breaks if you try to use it
>>interactively within rxvt/MinTTY/etc.  A cygwin-compiled version works
>>in all cases.
>
>I see, thanks for explaining that.  What exactly does happen when
>calling read() that means that pty input doesn't reach the program?

It's buffered differently.  MSVCRT thinks that Cygwin's ptys are pipes so
it buffers the input like a pipe rather than a terminal.

cgf

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