[PATCH] better systemctl completion

[foudfou <foudil.newbie+gmane@xxxxxxxxx>]

Hi all,

Attached is my proposal of a systemctl completion function. Compared to the existing function shipped with zsh, it brings the following enhancements:
- up-to-date command/arguments definitions
- finer per-command completion of units

Best,
Foudil

---
 Completion/Unix/Command/_systemctl |  339 ++++++++++++++++++++++++++++--------
 1 files changed, 264 insertions(+), 75 deletions(-)


diff --git a/Completion/Unix/Command/_systemctl b/Completion/Unix/Command/_systemctl
index 5dd35db..801a8e0 100644
--- a/Completion/Unix/Command/_systemctl
+++ b/Completion/Unix/Command/_systemctl
@@ -1,102 +1,291 @@
 #compdef systemctl
 
-# Completion for systemd's systemctl
-# Version 1.0 ARF 3 August 2011
+# Copyright (c) 2011 Foudil Brétel <foudil.newbie+zshsystemctl@xxxxxxxxx>
+#
+# This file is released under the GPLv3.
+#
+# inspired from _yum and systemctl-bash-completion.sh (shipped with systemctl)
+#
+# TODO: enable options after commands. Ex: systemctl list-units --all --full
 
-# list the unit completions.
-_systemd_units(){
-  local -a units
-  local expl
-  units=(${(f)"$( systemctl --full list-units | sed -e 's/ .*//' )"})
-  _wanted keys expl 'units' compadd "$units[@]"
-}
-
-# list the job completions.
-_systemd_jobs(){
-  local -a jobs
-  local expl
-  jobs=(${(f)"$( systemctl --full list-jobs | sed -e 's/ .*//' )"})
-  _wanted keys expl 'jobs' compadd "$jobs[@]"
-}
-
-# list the snapshot completions.
-_systemd_snapshots(){
-  local -a ss
-  local expl
-  ss=(${(f)"$(
-  	systemctl dump | sed -n -e 's/^-> Unit \(.*\.snapshot\):/\1/p'
-  )"})
-  _wanted keys expl 'snapshots' compadd "$ss[@]"
-}
-
-_systemctl(){
-  local -a _systemctl_cmds
+# Main dispatcher
+_systemctl()
+{
+  local curcontext="$curcontext" state lstate line
 
-  # Determine the sub commands
-  #$(systemctl --help  | sed -n -e 's/^  \([a-z]\)/\1/p' | sed -e 's/ .*//')
-  _systemctl_cmds=( 
-        list-units start stop reload restart try-restart reload-or-
-        restart reload-or-try-restart isolate kill is-active status show
-        reset-failed enable disable is-enabled load list-jobs cancel
-        monitor dump dot snapshot delete daemon-reload daemon-reexec show-
-        environment set-environment unset-environment default rescue
-        emergency halt poweroff reboot kexec exit
-  )
-
-  local curcontext="$curcontext" state line expl
-  typeset -A opt_args
-
-  # Initial flags
-  _arguments -A '-*' \
-    '--help[Show help]' \
+  # -s for aggregated options like -aP
+  _arguments -s \
+    {-h,--help}'[Show help]' \
     '--version[Show package version]' \
-    '(-a,--all)'{-a,--all}'[Show all units/properties, including dead/empty ones]' \
-    '--full[Dont ellipsize unit names on output]' \
+    {-t,--type=}'[List only units of a particular type]:unit type:(automount device mount path service snapshot socket swap target timer)' \
+    \*{-p,--property=}'[Show only properties by specific name]:unit property:' \
+    {-a,--all}'[Show all units/properties, including dead/empty ones]' \
     '--failed[Show only failed units]' \
+    "--full[Don't ellipsize unit names on output]" \
     '--fail[When queueing a new job, fail if conflicting jobs are pending]' \
-    '--ignore-dependencies[ignore dependencies]' \
-    '(-p,--privileged)'{-p,--privileged}'[Acquire privileges before execution]' \
-    '(-q,--quiet)'{-q,--quiet}'[Suppress output]' \
+    '--ignore-dependencies[When queueing a new job, ignore all its dependencies]' \
+    '--kill-mode=[How to send signal]:killmode:(control-group process)' \
+    '--kill-who=[Who to send signal to]:killwho:(main control all)' \
+    {-s,--signal=}'[Which signal to send]:signal:_signals' \
+    {-H,--host=}'[Show information for remote host]:userathost:_hosts_or_user_at_host' \
+    {-P,--privileged}'[Acquire privileges before execution]' \
+    {-q,--quiet}'[Suppress output]' \
     '--no-block[Do not wait until operation finished]' \
-    '--no-wall[Dont send wall message before halt/power-off/reboot]' \
-    '--no-reload[dont reload daemon configuration]' \
-    '--no-pager[Do use pager]' \
+    "--no-wall[Don't send wall message before halt/power-off/reboot]" \
+    "--no-reload[When enabling/disabling unit files, don't reload daemon configuration]" \
+    '--no-pager[Do not pipe output into a pager]' \
     '--no-ask-password[Do not ask for system passwords]' \
     '--order[When generating graph for dot, show only order]' \
     '--require[When generating graph for dot, show only requirement]' \
     '--system[Connect to system manager]' \
     '--user[Connect to user service manager]' \
     '--global[Enable/disable unit files globally]' \
-    '(-f,--force)'{-f,--force}'[When enabling unit files, override existing symlinks. When shutting down, execute action immediately]' \
+    {-f,--force}'[When enabling unit files, override existing symlinks. When shutting down, execute action immediately]' \
     '--defaults[When disabling unit files, remove default symlinks only]' \
-    '*::command:->subcmd' && return 0
+    '*::systemctl command:_systemctl_command'
+}
+
+_hosts_or_user_at_host()
+{
+  _alternative \
+    'users-hosts:: _user_at_host' \
+    'hosts:: _hosts'
+}
+
+(( $+functions[_systemctl_command] )) || _systemctl_command()
+{
+  local -a _systemctl_cmds
+  _systemctl_cmds=(
+    "list-units:List units"
+    "start:Start (activate) one or more units"
+    "stop:Stop (deactivate) one or more units"
+    "reload:Reload one or more units"
+    "restart:Start or restart one or more units"
+    "try-restart:Restart one or more units if active"
+    "reload-or-restart:Reload one or more units is possible, otherwise start or restart"
+    "reload-or-try-restart:Reload one or more units is possible, otherwise restart if active"
+    "isolate:Start one unit and stop all others"
+    "kill:Send signal to processes of a unit"
+    "is-active:Check whether units are active"
+    "status:Show runtime status of one or more units"
+    "show:Show properties of one or more units/jobs or the manager"
+    "reset-failed:Reset failed state for all, one, or more units"
+    "enable:Enable one or more unit files"
+    "disable:Disable one or more unit files"
+    "is-enabled:Check whether unit files are enabled"
+    "load:Load one or more units"
+    "list-jobs:List jobs"
+    "cancel:Cancel all, one, or more jobs"
+    "monitor:Monitor unit/job changes"
+    "dump:Dump server status"
+    "dot:Dump dependency graph for dot(1)"
+    "snapshot:Create a snapshot"
+    "delete:Remove one or more snapshots"
+    "daemon-reload:Reload systemd manager configuration"
+    "daemon-reexec:Reexecute systemd manager"
+    "show-environment:Dump environment"
+    "set-environment:Set one or more environment variables"
+    "unset-environment:Unset one or more environment variables"
+    "default:Enter system default mode"
+    "rescue:Enter system rescue mode"
+    "emergency:Enter system emergency mode"
+    "halt:Shut down and halt the system"
+    "poweroff:Shut down and power-off the system"
+    "reboot:Shut down and reboot the system"
+    "kexec:Shut down and reboot the system with kexec"
+    "exit:Ask for user instance termination"
+  )
 
-  # Complete subcommands.
   if (( CURRENT == 1 )); then
-    _describe -t commands "command" _systemctl_cmds
-    return
+    _describe -t commands 'systemctl command' _systemctl_cmds || compadd "$@"
+  else
+    local curcontext="$curcontext"
+
+    cmd="${${_systemctl_cmds[(r)$words[1]:*]%%:*}}"
+    # Deal with any aliases
+    case $cmd in
+      condrestart) cmd="try-restart";;
+      force-reload) cmd="reload-or-try-restart";;
+    esac
+
+    if (( $#cmd )); then
+      curcontext="${curcontext%:*:*}:systemctl-${cmd}:"
+
+      local update_policy
+      zstyle -s ":completion:${curcontext}:" cache-policy update_policy
+      if [[ -z "$update_policy" ]]; then
+        zstyle ":completion:${curcontext}:" cache-policy _systemctl_caching_policy
+      fi
+
+      _call_function ret _systemctl_$cmd || _message 'no more arguments'
+    else
+      _message "unknown systemctl command: $words[1]"
+    fi
+    return ret
   fi
+}
 
-  # handle arguments to the subcommands.
-  case $words[1] in
-  	start|restart|reload|stop|status|try-restart|reload-or-restart|reload-or-try-restart|isolate|kill|is-active|show|reset-failed|enable|disable|is-enabled|load)
-		# many units can be listed
-		_arguments "*:key:_systemd_units"
-	;;
+# Fills the unit lists
+_systemctl_all_units()
+{
+  if ( [[ ${+_sys_all_units} -eq 0 ]] || _cache_invalid SYS_ALL_UNITS ) &&
+    ! _retrieve_cache SYS_ALL_UNITS;
+  then
+    _sys_all_units=( $(systemctl list-units --full --all | cut -d' ' -f1 \
+      2>/dev/null) )
+    _store_cache SYS_ALL_UNITS _sys_all_units
+  fi
+}
 
-	cancel) _arguments "*:key:_systemd_jobs" ;;
+_systemctl_inactive_units()
+{
+  _sys_inactive_units=( $(systemctl list-units --full --all \
+    | awk '$3 != "active" {print $1}'  2>/dev/null) )
+}
 
-	# snapshots
-	snapshot) _normal ;;
-	delete) _arguments "*:key:_systemd_snapshots" ;;
+_systemctl_active_units()
+{
+  _sys_active_units=( $(systemctl list-units --full | cut -d' ' -f1 \
+    2>/dev/null) )
+}
 
-	# no arguments
-	dump|dot|monitor|daemon-reload|daemon-reexec|show-environment|default|rescue|emergency|halt|poweroff|reboot|kexec|exit|list-jobs|list-units)
-	;;
+_systemctl_failed_units()
+{
+  _sys_failed_units=( $(systemctl list-units --full --failed | cut -d' ' -f1
+    2>/dev/null) )
+}
+
+_filter_units_by_property () {
+  local property=$1 value=$2 ; shift ; shift
+  local -a units ; units=($*)
+  local -a props ; props=( $(systemctl show --property "$property" -- \
+    ${units[*]} | grep -v '^$') )
+  for ((i=0; $i < ${#units[*]}; i++)); do
+    if [[ "${props[i]}" = "$property=$value" ]]; then
+      echo "${units[i]}"
+    fi
+  done
+}
+
+# Completion functions for ALL_UNITS
+for fun in enable disable is-active is-enabled status show ; do
+  (( $+functions[_systemctl_$fun] )) || _systemctl_$fun()
+  {
+    _systemctl_all_units
+    compadd "$@" -a -- _sys_all_units
+  }
+done
+
+# Completion functions for STARTABLE_UNITS
+(( $+functions[_systemctl_start] )) || _systemctl_start()
+{
+  _systemctl_inactive_units
+  compadd "$@" -- $( _filter_units_by_property CanStart yes \
+    ${_sys_inactive_units[*]} | grep -Ev '\.(device|snapshot)$' )
+}
+
+# Completion functions for RESTARTABLE_UNITS
+for fun in restart reload-or-restart ; do
+  (( $+functions[_systemctl_$fun] )) || _systemctl_$fun()
+  {
+    _systemctl_all_units
+    compadd "$@" -- $( _filter_units_by_property CanStart yes \
+      ${_sys_all_units[*]} | grep -Ev '\.(device|snapshot|socket|timer)$' )
+  }
+done
+
+# Completion functions for STOPPABLE_UNITS
+for fun in stop kill try-restart condrestart ; do
+  (( $+functions[_systemctl_$fun] )) || _systemctl_$fun()
+  {
+    _systemctl_active_units
+    compadd "$@" -- $( _filter_units_by_property CanStop yes \
+      ${_sys_active_units[*]} )
+  }
+done
+
+# Completion functions for RELOADABLE_UNITS
+for fun in reload reload-or-try-restart force-reload ; do
+  (( $+functions[_systemctl_$fun] )) || _systemctl_$fun()
+  {
+    _systemctl_active_units
+    compadd "$@" -- $( _filter_units_by_property CanReload yes \
+      ${_sys_active_units[*]} )
+  }
+done
+
+# Completion functions for ISOLATABLE_UNITS
+(( $+functions[_systemctl_isolate] )) || _systemctl_isolate()
+{
+  _systemctl_all_units
+  compadd "$@" -- $( _filter_units_by_property AllowIsolate yes \
+    ${_sys_all_units[*]} )
+}
+
+# Completion functions for FAILED_UNITS
+(( $+functions[_systemctl_reset-failed] )) || _systemctl_reset-failed()
+{
+  _systemctl_failed_units
+  compadd "$@" -a -- _sys_failed_units || _message "no failed-unit found"
+}
+
+# Completion functions for JOBS
+(( $+functions[_systemctl_cancel] )) || _systemctl_cancel()
+{
+  compadd "$@" -- $( systemctl list-jobs | cut -d' ' -f1  2>/dev/null ) || \
+    _message "no job found"
+}
+
+# Completion functions for SNAPSHOTS
+(( $+functions[_systemctl_delete] )) || _systemctl_delete()
+{
+  compadd "$@" -- $( systemctl list-units --type snapshot --full --all \
+    | cut -d' ' -f1  2>/dev/null ) || _message "no snampshot found"
+}
+
+# Completion functions for ENVS
+(( $+functions[_systemctl_set-environment] )) || _systemctl_set-environment()
+{
+  compadd "$@" -S '' -- $( systemctl show-environment \
+    | sed 's_\([^=]\+=\).*_\1_' )
+}
+(( $+functions[_systemctl_unset-environment] )) || _systemctl_unset-environment()
+{
+  compadd "$@" -S '' -- $( systemctl show-environment \
+    | sed 's_\([^=]\+\)=.*_\1_' )
+}
+
+# no completion for:
+#   [STANDALONE]='daemon-reexec daemon-reload default dot dump emergency exit
+#                 halt kexec list-jobs list-units monitor poweroff reboot
+#                 rescue show-environment'
+#         [NAME]='snapshot load'
+
+_systemctl_caching_policy()
+{
+  local _sysunits
+  local -a oldcache
+
+  # rebuild if cache is more than a day old
+  oldcache=( "$1"(mh+1) )
+  (( $#oldcache )) && return 0
+
+  _sysunits=($(systemctl --full --all | cut -d' ' -f1))
+
+  if (( $#_sysunits )); then
+    for unit in $_sysunits; do
+      [[ "$unit" -nt "$1" ]] && return 0
+    done
+  fi
 
-	*) _message "unknown systemctl command: $words[1]" ;;
-  esac
+  return 1
 }
 
 _systemctl "$@"
 
+# Local Variables:
+# mode: sh
+# sh-indentation: 2
+# indent-tabs-mode: nil
+# sh-basic-offset: 2
+# End: