Using port drivers in OTP

Questions / Help
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Is there some pattern for using port drivers in OTP?

My plan is running some external programs for some amount of time.

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Explore the Erlang documentation’s tutorial on C Ports, an essential feature that facilitates seamless integration between Erlang and C programming languages. The tutorial provides detailed insights and guidance, offering developers a comprehensive resource to understand the intricacies of C Port. You also can find useful Building C/C++ | Rebar3 documentation useful or at Erlang.mk User Guide - related to which tool for build project you want to use. Plus, you can take a look to this topic Erlang Nodes and C Nodes.

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I might haved asked the wrong question. My plan is calling out for ffmpeg via open_port.

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There is no specific pattern for it. There is erlexec library that implements some convenience, but I have no personal experience with it. If you’re not planning to leverage it, several notes that I accumulated while working on similar externally running code. Most of these notes are clearly visible in OTP peer module (otp/lib/stdlib/src/peer.erl at master · erlang/otp · GitHub).

  • for every instance of the external executable, have a supervising Erlang process (peer implements a gen_server for that purpose)
  • you may need to use OS level signals (e.g. kill on Unix, executed with the same open_port approach) to control external executable behaviour)
  • be aware of how the executable operates with stdin/stdout (e.g. it may crash if stdin is abruptly closed, or stdout/stderr is not functioning)
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Thanks!