I think the thing I want to do is called GUI/command line wrapping sftp(1). I need an easy way to start that program and react on its output while running. Additionally I have to be able to send input to it, full interaction is required.
I tried forkpty (emulated TTY), but there wasn’t one good example findable using forkpty for that job, instead several warnings about overflows in in arguments and advisories not to use it. Another weird thing about this was the windowsize argument…
Please either give me one or many example(s) on how to call & interact with command line programs in C or another way of integrating sftp in an iPhone GUI
Rejoice! Expect was created to solve exactly your problem. It’s based on Tcl, which is not so pleasant, but the tool is pleasant, it’s really well designed, and there’s a good book by Don Libes, who created the tool.
Expect scripts are written in Tcl, but it is totally easy to integrate a Tcl script into a C program such that other parts of the C program don’t even know that Tcl is being used.