Edit

[EDIT] FILE: _loginctl

#compdef loginctl
# SPDX-License-Identifier: LGPL-2.1+

_loginctl_all_sessions() {
  local session description
  loginctl --no-legend list-sessions | while read -r session description; do
    _sys_all_sessions+=( "$session" )
    _sys_all_sessions_descr+=( "${session}:$description" )
  done
}

_loginctl_all_users() {
  local uid description
  loginctl --no-legend list-users | while read -r uid description; do
    _sys_all_users+=( "$uid" )
    _sys_all_users_descr+=( "${uid}:$description" )
  done
}

_loginctl_all_seats() {
  local seat description
  loginctl --no-legend list-seats | while read -r seat description; do
    _sys_all_seats+=( "$seat" )
    _sys_all_seats_descr+=( "${seat}:$description" )
  done
}

local fun
# Completion functions for SESSIONS
for fun in session-status show-session activate lock-session unlock-session terminate-session kill-session ; do
  (( $+functions[_loginctl_$fun] )) || _loginctl_$fun()
  {
    local -a _sys_all_sessions{,_descr}

_loginctl_all_sessions
    for _ignore in $words[2,-1]; do
      _sys_all_sessions[(i)$_ignore]=()
      _sys_all_sessions_descr[(i)$_ignore:*]=()
    done

if zstyle -T ":completion:${curcontext}:systemd-sessions" verbose; then
      _describe -t systemd-sessions session _sys_all_sessions_descr _sys_all_sessions "$@"
    else
      local expl
      _wanted systemd-sessions expl session compadd "$@" -a _sys_all_sessions
    fi
  }
done

# Completion functions for USERS
for fun in user-status show-user enable-linger disable-linger terminate-user kill-user ; do
  (( $+functions[_loginctl_$fun] )) || _loginctl_$fun()
  {
    local -a _sys_all_users{,_descr}
    zstyle -a ":completion:${curcontext}:users" users _sys_all_users

if ! (( $#_sys_all_users )); then
      _loginctl_all_users
    fi

for _ignore in $words[2,-1]; do
      _sys_all_users[(i)$_ignore]=()
      _sys_all_users_descr[(i)$_ignore:*]=()
    done

# using the common tag `users' here, not rolling our own `systemd-users' tag
    if zstyle -T ":completion:${curcontext}:users" verbose; then
      _describe -t users user ${_sys_all_users_descr:+_sys_all_users_descr} _sys_all_users "$@"
    else
      local expl
      _wanted users expl user compadd "$@" -a _sys_all_users
    fi
  }
done

# Completion functions for SEATS
(( $+functions[_loginctl_seats] )) || _loginctl_seats()
{
  local -a _sys_all_seats{,_descr}

_loginctl_all_seats
  for _ignore in $words[2,-1]; do
    _sys_all_seats[(i)$_ignore]=()
    _sys_all_seats_descr[(i)$_ignore:*]=()
  done

if zstyle -T ":completion:${curcontext}:systemd-seats" verbose; then
    _describe -t systemd-seats seat _sys_all_seats_descr _sys_all_seats "$@"
  else
    local expl
    _wanted systemd-seats expl seat compadd "$@" -a _sys_all_seats
  fi
}
for fun in seat-status show-seat terminate-seat ; do
  (( $+functions[_loginctl_$fun] )) || _loginctl_$fun()
  { _loginctl_seats }
done

# Completion functions for ATTACH
(( $+functions[_loginctl_attach] )) || _loginctl_attach()
{
  _arguments -w -C -S -s \
    ':seat:_loginctl_seats' \
    '*:device:_files'
}

# no loginctl completion for:
# [STANDALONE]='list-sessions list-users list-seats flush-devices'

(( $+functions[_loginctl_command] )) || _loginctl_command()
{
  local -a _loginctl_cmds
  _loginctl_cmds=(
    "list-sessions:List sessions"
    "session-status:Show session status"
    "show-session:Show properties of one or more sessions"
    "activate:Activate a session"
    "lock-session:Screen lock one or more sessions"
    "unlock-session:Screen unlock one or more sessions"
    "lock-sessions:Screen lock all current sessions"
    "unlock-sessions:Screen unlock all current sessions"
    "terminate-session:Terminate one or more sessions"
    "kill-session:Send signal to processes of a session"
    "list-users:List users"
    "user-status:Show user status"
    "show-user:Show properties of one or more users"
    "enable-linger:Enable linger state of one or more users"
    "disable-linger:Disable linger state of one or more users"
    "terminate-user:Terminate all sessions of one or more users"
    "kill-user:Send signal to processes of a user"
    "list-seats:List seats"
    "seat-status:Show seat status"
    "show-seat:Show properties of one or more seats"
    "attach:Attach one or more devices to a seat"
    "flush-devices:Flush all device associations"
    "terminate-seat:Terminate all sessions on one or more seats"
  )

if (( CURRENT == 1 )); then
    _describe -t commands 'loginctl command' _loginctl_cmds || compadd "$@"
  else
    local curcontext="$curcontext" _ignore

cmd="${${_loginctl_cmds[(r)$words[1]:*]%%:*}}"

if (( $#cmd )); then
      curcontext="${curcontext%:*:*}:loginctl-${cmd}:"

_call_function ret _loginctl_$cmd || _message 'no more arguments'
    else
      _message "unknown loginctl command: $words[1]"
    fi
    return ret
  fi
}

_arguments -s \
    {-h,--help}'[Show help]' \
    '--version[Show package version]' \
    \*{-p+,--property=}'[Show only properties by this name]:unit property' \
    {-a,--all}'[Show all properties, including empty ones]' \
    '--kill-who=[Who to send signal to]:killwho:(main control all)' \
    {-s+,--signal=}'[Which signal to send]:signal:_signals' \
    {-H+,--host=}'[Operate on remote host]:userathost:_sd_hosts_or_user_at_host' \
    {-M+,--machine=}'[Operate on local container]:machine:_sd_machines' \
    {-l,--full}'[Do not ellipsize output]' \
    '--no-pager[Do not pipe output into a pager]' \
    '--no-legend[Do not show the headers and footers]' \
    '--no-ask-password[Do not ask for system passwords]' \
    {-n+,--lines=}'[Number of journal entries to show]' \
    {-o+,--output=}'[Change journal output mode]:output modes:_sd_outputmodes' \
    '*::loginctl command:_loginctl_command'

CANCEL