Pipe behavior

[Randall R Schulz]

Steven,

At 16:28 2003-04-03, you wrote:
>Hello,
>
>I have a question about pipe behavior.  I wrote a simple program that
>does a printf, sleeps for 5 seconds and then another printf.  If I run
>the program with the following way:  $ ./simple | cat  The output is
>delayed until the program finished.  I guessed that the pipe is buffered
>and doesn't flush until it is closed when the program ends.  But then I
>ran the same program as an emacs subprocess and attached a buffer to it.
>In this scenario the first printf is displayed, 5 seconds pass and then
>the second printf is displayed.  Emacs also uses pipes so I do not
>understand why the behavior is different.

Pipes don't buffer in the manner you describe, but the standard I/O 
library does when its output is directed to a pipe or a plain file.

Are you sure that Emacs uses pipes and not ptys (pseudo-ttys)?

Which Emacs are you using? Cygwin or Windows?


>Thanks
>Steven Kilby


Randall "We don't need no stinkin' disclaimers" Schulz 


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