How can a Lazarus/FPC program that is executing a command via TProcessdetect an input prompt and create a graphical dialog for the input?

e.g. say I execute an ssh command via TProcess which requires a password to be input - how could it detect it, prompt for it with a graphical dialog and pass it on for the command to continue?

There's no such a way AFAIK, you have to know exactly what your program is executing. Therefore you have to always give the graphical input dialog (and it's up to you when to show it, before or during execution).

There is no way to do this in general.

There are some unix tools that attempt to do this ('expect'), but all of them require some form of script, taylored to the tools that you want to use it for.

Michael.

Considering the particular case of SSH, I think there's a related daemon which can detect whether sshd is asking for a passphrase and present a dialog(ue). I've not used it, and can't remember the extent to which it e.g. worked across networked systems.

I think the question needs to be clarified: would the requirement be better served by (a) finding some way for an alternative daemon or API to display the prompt or (b) investigating how to hook the TProcess child's request for input.

Considering the particular case of SSH, I think there's a related daemon which can detect whether sshd is asking for a passphrase and present a dialog(ue). I've not used it, and can't remember the extent to which it e.g. worked across networked systems.

Doesn't ssh have according parameters, so that it must not ask the user?

I think the question needs to be clarified: would the requirement be better served by (a) finding some way for an alternative daemon or API to display the prompt or (b) investigating how to hook the TProcess child's request for input.

I'd write a new GUI around the worker code, so that ssh (or whatsoever) can be used as a library in every program. I did this already for tools like gzip, so that these can be used in my own console or GUI programs.

DoDi

That wasn't what I had in mind though. See ssh-agent.

After further consideration I think what I am thinking of is a TProcess like object that emulates a console, so it "types" the command and receives input as well as prompts. Is there an FPC library that does something like that?

After further consideration I think what I am thinking of is a TProcess like object that emulates a console, so it "types" the command and receives input as well as prompts. Is there an FPC library that does something like that?

You don't need a console. Simply create a bidirectional pipe, or two unidirectional ones, and connect it to the stdin/stdout of the process. Then parse what the process outputs, and when you find the prompt, send it your input.

DoDi