example.cf

bundle agent main
{
  methods:
      "" usebundle => "HSLinux:append_hell";
}

body file control
{
      inputs => { "$(sys.libdir)/stdlib.cf" };
      namespace => "HSLinux";
}

bundle agent append_hell
{
  files:
    any::
      "/tmp/whatever-$(sys.fqhost)"
      edit_line => default:append_if_no_line("APPEND=HELL"),
      classes => default:results("namespace", "added_ready");

  commands:
    HSLinux:added_ready_repaired::
      "/bin/true" classes => default:if_ok("ran_true");

  reports:
    DEBUG|DEBUG_append_hell::
      "Considering: /tmp/whatever-$(sys.fqhost)";

    HSLinux:ran_true::
      "I ran true to discover the append ever hell.";
}