Execing Processes in Elixir

Here’s the translation of the Go code to Elixir, with explanations in Markdown format suitable for Hugo:

Our example demonstrates how to replace the current Elixir process with another executable. This is similar to the classic exec function in Unix-like operating systems.

defmodule ExecingProcesses do
  def main do
    # For our example we'll exec `ls`. Elixir doesn't require an
    # absolute path to the binary we want to execute, so we can
    # use `ls` directly.
    binary = "ls"

    # We'll give `ls` a few common arguments. In Elixir, we pass
    # these as a list of strings.
    args = ["-a", "-l", "-h"]

    # In Elixir, we don't need to explicitly pass the environment
    # variables. The current environment is used by default.

    # Here's the actual System.cmd/3 call. If this call is
    # successful, it will return the output of the command.
    # If there is an error, it will raise an exception.
    try do
      {output, status} = System.cmd(binary, args)
      IO.puts(output)
    rescue
      e in ErlangError -> IO.puts("Failed to execute command: #{inspect(e)}")
    end
  end
end

ExecingProcesses.main()

When we run our program, it executes the ls command:

$ elixir execing_processes.exs
total 16K
drwxr-xr-x  4 user user 4.0K Oct 3 16:29 .
drwxr-xr-x 91 user user 4.0K Oct 3 12:50 ..
-rw-r--r--  1 user user 1.3K Oct 3 16:28 execing_processes.exs

Note that Elixir doesn’t offer a direct equivalent to Unix’s fork or exec functions. Instead, it provides a rich set of primitives for concurrent and distributed programming through its Actor model and OTP behaviors. The System.cmd/3 function, which we used in this example, is often sufficient for running external commands.

For more complex scenarios involving process management, you might want to look into Erlang’s :os.cmd/1 or the Port module, which allow for more fine-grained control over external processes.