add list command and tighten up code

changelog.txt

@@ -29,7 +29,7 @@ Template for new versions:
 ## New Tools
 - `fix/wildlife`: prevent wildlife from getting stuck when trying to exit the map. This fix needs to be enabled manually in `gui/control-panel` on the Bug Fixes tab since not all players want this bug to be fixed.
 - `immortal-cravings`: allow immortals to satisfy their cravings for food and drink
-- `justice`: various functions pertaining to the justice system, currently with a command to pardon a unit's prison sentence.
+- `justice`: various functions pertaining to the justice system, currently with a command to pardon a unit's prison sentence
 
 ## New Features
 - `force`: support the ``Wildlife`` event to allow additional wildlife to enter the map

docs/justice.rst

@@ -2,7 +2,7 @@ justice
 =======
 
 .. dfhack-tool::
-    :summary: Commands related to the justice system.
+    :summary: Mess with the justice system.
     :tags: fort armok units
 
 This tool allows control over aspects of the justice system, such as the
@@ -12,15 +12,23 @@ Usage
 -----
 
 ::
+    justice [list]
     justice pardon [--unit <id>]
 
 Pardon the selected unit or the one specified by unit id (if provided).
 Currently only applies to prison time and doesn't cancel beatings or
 hammerings.
 
+Examples
+--------
+
+``justice``
+    List the convicts currently serving sentences.
+``justice pardon``
+    Commutes the sentence of the currently selected convict.
 
 Options
 -------
 
 ``-u``, ``--unit <id>``
-    Specifies the unit id of the target of the command.
+    Specifies a specific unit instead of using a selected unit.

justice.lua

@@ -1,6 +1,24 @@
-
 local argparse = require('argparse')
 
+local TICKS_PER_SEASON_TICK = 10
+local TICKS_PER_DAY = 1200
+
+local function list_convicts()
+    local found = false
+    for _,punishment in ipairs(df.global.plotinfo.punishments) do
+        local unit = df.unit.find(punishment.criminal)
+        if unit and punishment.prison_counter > 0 then
+            found = true
+            local days = math.ceil((punishment.prison_counter * TICKS_PER_SEASON_TICK) / TICKS_PER_DAY)
+            print(('%s (id: %d): serving a sentence of %d day(s)'):format(
+                dfhack.units.getReadableName(unit), unit.id, days))
+        end
+    end
+    if not found then
+        print('No criminals currently serving sentences.')
+    end
+end
+
 local function pardon_unit(unit)
     for _,punishment in ipairs(df.global.plotinfo.punishments) do
         if punishment.criminal == unit.id then
@@ -14,29 +32,30 @@ end
 local function command_pardon(unit_id)
     local unit = nil
     if not unit_id then
-        unit = dfhack.gui.getSelectedUnit()
-        if not unit then qerror("No unit selected!") end
+        unit = dfhack.gui.getSelectedUnit(true)
+        if not unit then qerror('No unit selected!') end
     else
         unit = df.unit.find(unit_id)
-        if not unit then qerror(("No unit with id %i"):format(unit_id)) end
+        if not unit then qerror(('No unit with id %d'):format(unit_id)) end
     end
-    if unit then pardon_unit(unit) end
+    pardon_unit(unit)
 end
 
 local unit_id = nil
 
-local args = {...}
-
-local positionals = argparse.processArgsGetopt(args,
-    {'u', 'unit', hasArg=true, handler=function(optarg) unit_id = optarg end}
+local positionals = argparse.processArgsGetopt({...},
+    {
+        {'u', 'unit', hasArg=true,
+            handler=function(optarg) unit_id = argparse.nonnegativeInt(optarg, 'unit') end},
+    }
 )
 
 local command = positionals[1]
 
-if command == "pardon" then
+if command == 'pardon' then
     command_pardon(unit_id)
-elseif not command then
-    qerror('Missing command')
+elseif not command or command == 'list' then
+    list_convicts()
 else
-    qerror(("Unrecognised command: %s"):format(command))
+    qerror(('Unrecognised command: %s'):format(command))
 end