Re: Faking a TTY on a pipe/socketpair

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.