Hi there, I’m having some trouble with the “System” module, specifically the cmd function. My code is the following, which is exactly the same as the documentation, StackOverflow/Elixir forum answers, etc:

System.cmd("echo", ["Hello"])

I’m getting the following error:

** (ErlangError) Erlang error: :enoent
    (elixir 1.10.4) lib/system.ex:795: System.cmd("echo", ["Hello"], [])
    (elixir 1.10.4) lib/code.ex:926: Code.require_file/2

I understand the “enoent” means “No such file or directory”, however, I don’t understand what file or directory could possibly be required in this case. It’s probably an elementary mistake which wouldn’t surprise me as I’m new to Elixir/Erlang. There are 2 things worth mentioning, in my opinion. The first is that surrounding the words “echo” and “Hello” in single quotes instead of double quotes, so System.cmd(‘echo’, [‘Hello’]), produces a different error:

** (FunctionClauseError) no function clause matching in System.cmd/3

    The following arguments were given to System.cmd/3:

        # 1
        'echo'

        # 2
        ['Hello']

        # 3
        []

    Attempted function clauses (showing 1 out of 1):

        def cmd(+command+, +args+, +opts+) when -is_binary(command)- and +is_list(args)+

    (elixir 1.10.4) lib/system.ex:782: System.cmd/3
    (elixir 1.10.4) lib/code.ex:926: Code.require_file/2

probably unrelated although I’m guessing this means that double quotes and single quotes are different in elixir. The other thing is that the following command works:

IO.puts "echo Hello" |> String.to_charlist |> :os.cmd

Although this one seems to return the result of running the command instead of directly running it in the running shell, hence the IO.puts, and I assume this isn’t the same behaviour as System.cmd
My apologies for the long post, but hopefully we can clear some things up here, and thanks in advance