zsh/Completion/Unix/Command/_initctl

#compdef initctl start stop restart reload status
# Written by Bernhard Tittelbach
# based on completion script by Mildred

typeset -g -a -U _initctl_events_list _initctl_eventargs_list

# run show-config -e and if possible parse out all events and KEY= arguments
# otherwise provide some common values
_initctl_fillarray_events_args ()
{
  setopt extendedglob
  local showconfig="$(initctl show-config -e 2>| /dev/null)"
  if [[ -n "$showconfig" ]]; then
    _initctl_events_list=()
    _initctl_eventargs_list=()
    for cline in "${(f)showconfig}"; do
      if [[ "$cline" == (#s)\ \ (stop\ on|start\ on|emit)\ (#b)([[:alpha:]-_]##)(*)(#e) ]]; then
        _initctl_events_list+=($match[1])
        # this is a bit tricky, we take the string right of the matched event
        # and parse for \sUPPERCASE=\S (in perl-re syntax) substrings until there are no more matches
        # since we can't do multiple matches, we concatenated the remaining strings and try again
        local stml="$match[2]"
        while [[ "$stml" == (#b)(*)\ ([[:upper:]_]##\=)[^[:space:]](#b)(*) ]]; do
          _initctl_eventargs_list+=($match[2])
          stml="$match[1] $match[3]"
        done
        unset stml
      fi
    done
  else
    _initctl_events_list=( socket login-session-start desktop-session-start virtual-filesystems local-filesystems remote-filesystems all-swaps filesystem mounting mounted net-device-up start-portmap runlevel unmounted-remote-filesystems )
    _initctl_eventargs_list=( PRIMARY_DEVICE_FOR_DISPLAY= EXIT_STATUS= EXIT_SIGNAL= RUNLEVEL= MOUNTPOINT= TYPE= INTERFACE= )
  fi
  return 0
}

# list all upstart jobs, i.e. all files in /etc/init/
_initctl_helper_jobs()
{
    _path_files -W "/etc/init/" -g "*.conf(-.:r)"
}

# list events, generate array if necessary
_initctl_known_events()
{
  [[ ${#_initctl_events_list} -eq 0 ]] && _initctl_fillarray_events_args
  _values "Event" "$_initctl_events_list[@]"
}

# list events, allow multiple choices, generate array if necessary
_initctl_multiple_known_events()
{
  [[ ${#_initctl_events_list} -eq 0 ]] && _initctl_fillarray_events_args
  _values -s "," "event" "$_initctl_events_list[@]"
}

# list KEY= arguments, generate array if necessary
_initctl_known_eventargs()
{
  [[ ${#_initctl_eventargs_list} -eq 0 ]] && _initctl_fillarray_events_args
  _values "argument key" "$_initctl_eventargs_list[@]"
}

# describe and offer commands for initctl, then call matching completion function
_initctl_command()
{
    local cmds
    cmds=(
        start:"Start jobs"
        stop:"Stop jobs"
        restart:"Restart jobs"
        reload:"Send SIGHUP to process instance"
        status:"Query status of jobs"
        list:"List known jobs"
        emit:"Emit an event"
        reload-configuration:"tell init to reload config files (generally inotify is used)"
        version:"Request the version of the init daemon"
        log-priority:"Change the minimum priority of log messages from the init daemon"
        show-config:"Show start/stop/emit for processes"
        check-config:"Find jobs than can't be started"
        help:"display list of commands"
    )

    if (( CURRENT == 1 )); then
        _describe -t command "initctl command" cmds
    fi

    local cmd=$words[1]

    local curcontext="${curcontext%:*}:initctl-${cmd}"
    _call_function ret _initctl_${cmd_completion_funcs[${cmd}]-${cmd_completion_default}}
}

# completion for start/stop/restart/reload i.e. anything that take one job and multiple KEY= arguments's
_initctl_startstop()
{
    _arguments \
        '--no-wait[do not wait for operation to complete before exiting]' \
        "${common_args[@]}" \
        ':upstart job:_initctl_helper_jobs' \
        '*::argument key:_initctl_known_eventargs'
}

# completion for anything that takes one job
_initctl_argjob()
{
    _arguments \
        "${common_args[@]}" \
        ':upstart job:_initctl_helper_jobs' \
        '*::'
}

# completion for emit, providing options,  one event and multiple KEY= arguments's
_initctl_emit()
{
    _arguments \
        '--no-wait[do not wait for event to finish before exiting]' \
        "${common_args[@]}" \
        ':event:_initctl_known_events' \
        '*::argument key:_initctl_known_eventargs'
}

# the fallback, just the options
_initctl_basic()
{
    _arguments \
        "${common_args[@]}"
}

# completion for show-config, additional option and one job
_initctl_show-config()
{
    _arguments \
      "(-e --enumerate)"{-e,--enumerate}"[enumerate emit lines]" \
        "${common_args[@]}" \
        '::upstart job:_initctl_helper_jobs' \
        '*::'
}

# completion for show-config, additional options and one job
_initctl_check-config()
{
    _arguments \
      "(-i --ignore-events)"{-i,--ignore-events}"[list of comma-separated events to ignore]:Events:_initctl_multiple_known_events" \
      "(-w --warn)"{-w,--warn}"[treat any unknown jobs or events as error]" \
        "${common_args[@]}" \
        '::upstart job:_initctl_helper_jobs' \
        '*::'
}

# after defining above functions, overwrite _initctl function so helper-functions are loaded only once
_initctl()
{
  local -a common_args
  common_args=(
    '--session[use D-Bus session bus to connect to init daemon (for testing)]'
    '--system[talk via DBUS system bus instead of socket]'
    '(-q --quiet)'{-q,--quiet}'[reduce output to errors only]'
    '(-v --verbose)'{-v,--verbose}'[increase output to include informational messages]'
    '--dest=[D-Bus name for init, defaults to com.ubuntu.Upstart]'
    '--help[display help and exit]'
    '--version[output version information and exit]'
  )

  # map each initctl function to a completion function
  local -A cmd_completion_funcs
  cmd_completion_funcs=( start startstop stop startstop restart startstop reload startstop show-config show-config status argjob emit emit check-config check-config )

  # define fallback completion function
  local cmd_completion_default=basic

  # depending on which command was used, call different completion functions
  case $service in
    initctl)
      _arguments "${common_args[@]}" '*::initctl command:_initctl_command'
    ;;
    start|stop|restart|reload|status)
      _call_function ret _initctl_${cmd_completion_funcs[${service}]-${cmd_completion_default}}
    ;;
    *)  return 1  ;;
  esac
}

_initctl "$@"