Re: how to assert user input to fifo to then read from it

[Alex fxmbsw7 Ratchev]

On Thu, Aug 25, 2022, 14:27 Alex fxmbsw7 Ratchev <fxmbsw7@gmail.com> wrote:

>
>
> On Thu, Aug 25, 2022, 13:32 Greg Wooledge <greg@wooledge.org> wrote:
>
>> On Thu, Aug 25, 2022 at 11:36:11AM +0200, Alex fxmbsw7 Ratchev wrote:
>> > im doing some apt update cmds script
>> > in there i realized i need detached input for , when as dedicated auto
>> > updater used , a question appears , to answer this
>> > ( seeing by log then reacting to via printf to fifo , and checking then
>> log
>> > further )
>> >
>> > the script yet is attached
>> > the in question is line 20 , it does exec <"$fi"
>> > .. and my question is what previously to exec to put scripts stdin ( may
>> > not be tty .. ? ) into that fifo , then that the exec < that_fifo
>> >
>> > understood halfways ?
>>
>> If we remove the FIFO from the equation, it sounds like you want to
>> inject some scripted data into the terminal's input buffer.
>>
>
> i try an auto updater, that prints to stdout and tee -a logfile
> that autoupdater be run via sysvinit , and ( dennis hinted it out ,
> noninteractive something , but i need this code)
> but the idea is run dedicated autoupdater , and have coded the possibility
> that when it hangs on dpkg question, via fifo to input to it
>
> i learnt roughly only fifos will work for intercomm
>
> and in that, i figured, i need the code to delegate user input to fifo ,
> which then gets to be stdin of the runtime
>
> .. script start , put to-script fd to fifo , and set scripts stdin fd be
> from that fifo
>
> i can imagine , exec <fifo , ( apt dpkg commands
> ..<abort>
> a cat >fifo be foreground process
> while apt dpkg commands run in background , or coproc
>
> .. complicated
>

i think something in the direction might work

script starts , exec > tee log , mkfifo fi , start coproc with the chain
apt cmds, with input from fifo
and finally, a cat >fi foreground .. .. .. ?


> thanks much !
>
> There's this:
>>
>> greg@remote:/home/greybot/factoids$ cat tiocsti ; echo
>> The TIOCSTI ioctl() command lets you insert input into a terminal
>> driver's queue. "Simulate Terminal Input".
>>
>> If you can do the injection in C, you can use that.
>>
>> Otherwise, maybe you can do something with tmux or screen?  I don't know
>> those programs well enough.
>>
>> Or if all else fails, there's always Expect.
>>
>>