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From: Muttley@DastartdlyHQ.org
Newsgroups: comp.unix.programmer
Subject: Re: Faking a TTY on a pipe/socketpair
Date: Sun, 17 Nov 2024 18:39:16 -0000 (UTC)
Organization: A noiseless patient Spider
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On Sun, 17 Nov 2024 17:48:23 -0000 (UTC)
Kaz Kylheku <643-408-1753@kylheku.com> boring babbled:
>On 2024-11-16, Muttley@dastardlyhq.com <Muttley@dastardlyhq.com> wrote:
>> So my question is - is there a way to set up a pipe or socketpair** so that
>> it appears to be a tty from the exec'd programs point of view, eg ttyname()
>> returns non null?
>[...]
>> ** Yes I know about the master-slave ptm,pts approach and I have done that
>in 
>> the past but its complete overkill for this purpose.
>
>No; you need a master/slave pseudo TTY pair connected to an active
>process, which forwards between that and the socketpair or pipe.

I figured as much but thought I'd ask, you never know.

>Sockets and pipes cannot be given window dressing so that they look
>like tty's. When the standard input (or output) of a process is a tty,
>and that process cares about it, it will likely try operations like
>tcgetattr.

The only think I suspect this util cares about is whether its having a file
redirected into its stdin and uses isatty() to find out. Its behaviour when
injesting a file is to take it all in the speak the lot instead of line by
line. Why I don't know, it would make little to no difference to the output.