2011/2/6 Jukka Tuominen <jukka.tuomi...@finndesign.fi>: > [...] > One more requirement that I forget to mention is that it should also > be possible to handle "expect" type of "automated conversations". > [...]
Hello, if you want I/O redirection, you should, for example, use the procedure process [1] instead of system. > [...] > You can pass several independent commands with system/output without > problem, but I had difficulties in figuring out how to log into > different machines, change the user etc. > [...] Executing remote commands can for be done by passing the command to an SSH client, for example, instead of directly handing it to the local shell. > [...] > where you need to pass answers interactively or otherwise move > between various modes (which expect can automate). > [...] Interactive communication with a shell or other program, whether local or remote doesn't really matter, can be somewhat more complicated, though. I don't know of any existing Scheme library that simplifies the communication with an interactive subprocess via an input and an output port in a similar way as expect does. It is certainly possible to create equivalent code in Racket and the fact that regular expression matching can be directly applied to input ports is certainly helpful for such an endeavour. But there are some potential pitfalls like commands behaving entirely differently depending on whether their I/O file descriptors are connected to a (pseudo-)terminal or some other communications channel or output containing terminal control escape sequences. Ciao, Thomas [1] http://docs.racket-lang.org/reference/subprocess.html?q=process#(def._((lib._racket/system..rkt)._process)) -- When C++ is your hammer, every problem looks like your thumb. _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
