{ writeExecline, getBins, pkgs, writeRustSimple }:
let

  bins = getBins pkgs.rlwrap [ "rlwrap" ]
    // getBins pkgs.s6-portable-utils [ { use = "s6-cat"; as = "cat"; } "s6-test" ]
    // getBins pkgs.execline [ "execlineb" ];

  # minimal execline shell
  shell =
    let
      prompt = [ "if" [ "printf" ''\e[0;33me>\e[0m '' ] ];
    in
      writeExecline "execline-shell" {} ([
        bins.rlwrap
          "--remember"
          "--quote-characters" "\""
          "--complete-filenames"
          "--ansi-colour-aware"
      ] ++ prompt ++ [
        "forstdin" "-d\n" "cmd"
        "importas" "cmd" "cmd"
        "foreground" [ bins.execlineb "-Pc" "$cmd" ]
      ] ++ prompt);

  e = pkgs.writers.writeDash "e" ''
    set -e
    # if there is no argument, we start the shell, else we call execlineb directly
    if [ $# -eq 0 ]; then
      ${shell}
    else
      export EXECLINE_STRICT=2
      ${run-cmd-line-block} "$@"
    fi
  '';

  run-cmd-line-block = writeRustSimple "run-cmd-line-block" {} ./run-cmd-line-block.rs;
in { inherit e; }