Add procmon plugin with live process panel (#301)

* Add procmon plugin with live process panel New Noctalia plugin: bar widget shows CPU/RAM usage and process count; floating panel has a sortable, searchable process table with per-process kill. Background service samples ps and /proc stats and publishes via plugin state. * Throttle data-driven panel renders Rebuild table at most every 500ms to stay within the panel update CPU budget. User interactions still render immediately; only state watches and the tick go through maybeRender(). * Update procmon deps and fix timestamp precision Document head, grep, and cat as required commands. Correct refresh interval default to 1000 ms. Sample refreshedAtMs in milliseconds.
2026-08-08 15:40:32 -04:00
parent 936f412599
commit 2b10a25ee0
7 changed files with 963 additions and 0 deletions
@@ -0,0 +1,60 @@
+# Process Monitor
+
+A bottom-style process monitor for Noctalia: live CPU/RAM/swap bars and a
+sortable, searchable process table with a per-process kill action, all in a
+panel. Great for spotting a runaway process or a zombie and killing it without
+opening a terminal.
+
+## Plugin
+
+| Field   | Value                                                    |
+| ------- | -------------------------------------------------------- |
+| ID      | `weinguyen/procmon`                                      |
+| Entries | Bar widget: `widget`; panel: `panel`; service: `service` |
+
+## Requirements
+
+Install `ps`, `kill`, `head`, `grep` and `cat` on `PATH` (all are present on
+virtually every Linux distribution).
+
+## Usage
+
+Add the **Process Monitor** widget to a bar. It shows the current CPU and RAM
+usage (plus the process count). Click the widget to toggle the process panel:
+
+```sh
+noctalia msg panel-toggle weinguyen/procmon:panel
+```
+
+The panel shows CPU, RAM and swap bars with the 1/5/15-minute load averages,
+then a process table. Sort by the column dropdown (PID, CPU%, MEM%, RSS,
+COMMAND) and flip asc/desc with the arrow button. Type in the filter box to
+match a process by name, user or PID. Click the ✕ button on a row to run the
+configured kill command against that PID (default `kill -TERM`). Zombie
+processes are tinted with the error color so they stand out.
+
+The table refreshes on the interval set in the `refresh_interval` setting. The
+panel re-renders automatically as new samples arrive, so the view stays live
+while it is open.
+
+## Settings
+
+| Setting            | Type     | Default      | Description                                                                                |
+| ------------------ | -------- | ------------ | ------------------------------------------------------------------------------------------ |
+| `refresh_interval` | `int`    | `1000`       | Process resample interval in milliseconds. (default 1000)                                  |
+| `sort_by`          | `select` | `cpu`        | Initial sort column when the panel opens (`cpu`, `mem`, `pid`, `cmd`).                     |
+| `kill_command`     | `string` | `kill -TERM` | Command run against a selected PID; the PID is appended. Empty falls back to `kill -TERM`. |
+| `show_count`       | `bool`   | `true`       | Bar widget also shows the total process count.                                             |
+
+## Notes
+
+- **Spawns processes.** A background service runs `ps` on every refresh
+  interval and `runAsync` runs the configured `kill_command` when a row's ✕ is
+  clicked. There is no confirmation dialog, so check the PID before clicking.
+- The bar widget only renders data the service publishes; it never runs
+  commands. The panel runs the configured `kill_command` when a row's ✕ is
+  clicked.
+- Requires `plugin_api = 12`. CPU%, RAM%, swap and the 1/5/15-minute load
+  averages are sampled from `/proc` (`/proc/stat`, `/proc/meminfo`,
+  `/proc/loadavg`) by the service, so they work with no separate system-monitor
+  dependency.
@@ -0,0 +1,460 @@
+--!nonstrict
+-- Process Monitor — panel. Renders the process table + live system bars.
+-- Sort/filter state lives here (a view concern); data comes from the service.
+
+local sortKey = "cpu"
+local sortDir = "desc"
+local filter = ""
+
+-- Per-column display unit: "pct" shows percent, "raw" shows the absolute
+-- figure. Clicking the %CPU/%MEM header toggles it. MEM raw = RSS in MB; CPU
+-- raw = cumulative CPU time (ps time=), a real number distinct from the %.
+-- (ponytail: a per-interval CPU% needs two /proc/pid/stat samples and a diff,
+-- too heavy for the update budget - the cumulative time is a free proxy.)
+local cpuUnit = "pct"
+local memUnit = "pct"
+
+-- Cap how many rows we render so a single rebuild stays under the panel
+-- update CPU budget. Rows are shown in sorted order, so the highest-sorting
+-- processes are always visible. (200 rows * ~7 ui nodes blew the budget.)
+local MAX_ROWS = 80
+
+-- Cheap fingerprint of everything the table shows, so the 1s tick only rebuilds
+-- the heavy UI tree when the data actually changed. Rebuilding 200 rows every
+-- second exceeded the panel update CPU budget; sampling the first SIG_SAMPLE
+-- rows (ps output is pid-ordered) catches CPU/mem/rss movement without the cost.
+local SIG_SAMPLE = 40
+local lastSig = nil
+
+-- Throttle data-driven renders. The service can sample faster than the panel can
+-- rebuild its table, and every state.set fires a watch: at 250ms that was ~16
+-- full rebuilds/sec of 80 rows, which blew the panel update CPU budget and got
+-- the panel disabled. User interactions (toggle/filter/sort) still render()
+-- immediately; only the data watches and the tick go through maybeRender().
+local lastRenderMs = 0
+local MIN_RENDER_MS = 500
+
+-- Kill column is a fixed width at the end of every row; all other columns are
+-- flexGrow shares so the header and data rows always align and never overflow.
+local KILL_W = 30
+
+local function cfg(key)
+	return noctalia.getConfig(key)
+end
+
+local function st(key)
+	return noctalia.state.get(key)
+end
+
+-- Draft value while the Refresh slider is being dragged; committed to state on
+-- release (audio-switcher pattern). The service watches "refreshMs" and re-arms
+-- its sampler timer, which is what actually changes the fetch speed. Declared
+-- after cfg/st (Luau: forward refs to a later local compile as globals -> nil).
+local refreshDraft = nil
+local function refreshMs()
+	return tonumber(st("refreshMs") or cfg("refresh_interval")) or 1000
+end
+local function commitRefresh()
+	if refreshDraft then
+		noctalia.state.set("refreshMs", refreshDraft)
+		refreshDraft = nil
+	end
+end
+
+local function signature()
+	local stats = st("stats") or {}
+	local cpuPct = stats.cpu and stats.cpu.usagePercent or 0
+	local ramPct = stats.ram and stats.ram.usagePercent or 0
+	local procs = st("procs") or {}
+	local n = #procs
+	local s = tostring(n) .. "|" .. filter .. "|" .. sortKey .. sortDir
+		.. "|" .. tostring(cpuPct) .. "|" .. tostring(ramPct)
+		.. "|" .. cpuUnit .. memUnit
+	local upto = n < SIG_SAMPLE and n or SIG_SAMPLE
+	for i = 1, upto do
+		local p = procs[i]
+		if p then
+			s = s .. "|" .. tostring(p.pid) .. ":" .. tostring(math.floor((p.cpu or 0) * 10))
+				.. ":" .. tostring(math.floor((p.mem or 0) * 10))
+				.. ":" .. tostring(math.floor((p.rssMb or 0) / 16))
+		end
+	end
+	return s
+end
+
+local function tr(key, subst)
+	return noctalia.tr(key, subst)
+end
+
+local function fmtMem(mb)
+	if mb == nil then
+		return "—"
+	end
+	if mb >= 1024 then
+		return string.format("%.1fG", mb / 1024)
+	end
+	return string.format("%.0fM", mb)
+end
+
+local function trunc(s, n)
+	if #s <= n then
+		return s
+	end
+	return s:sub(1, n - 1) .. "…"
+end
+
+local function killPid(pid)
+	local cmd = cfg("kill_command")
+	if cmd == "" then
+		cmd = "kill -TERM"
+	end
+	noctalia.runAsync(cmd .. " " .. pid)
+end
+
+-- ── stats bars ──────────────────────────────────────────────────────────────
+
+local function statBar(label, glyph, pct, sub)
+	local pct0 = math.max(0, math.min(100, pct or 0))
+	return ui.row({ gap = 8, align = "center", flexGrow = 1 }, {
+		ui.glyph({ name = glyph, size = 16 }),
+		ui.label({ text = label, fontSize = 11, color = "on_surface_variant" }),
+		ui.progress({ progress = pct0 / 100, flexGrow = 1, height = 8 }),
+		ui.label({ text = sub, fontSize = 11, textAlign = "end" }),
+	})
+end
+
+local function renderStats()
+	local stats = st("stats") or {}
+	local cpu = stats.cpu
+	local ram = stats.ram
+	local swap = stats.swap
+
+	local swapPct = 0
+	local swapSub = "—"
+	if swap and swap.totalMb and swap.totalMb > 0 then
+		swapPct = swap.usedMb / swap.totalMb * 100
+		swapSub = string.format("%.0f/%.0fM", swap.usedMb, swap.totalMb)
+	end
+
+	local loadSub = "—"
+	if stats.loadAvg then
+		loadSub = string.format("%.2f %.2f %.2f", stats.loadAvg[1], stats.loadAvg[2], stats.loadAvg[3])
+	end
+
+	-- The render path must never throw: any stats field may be nil (seed
+	-- stats, or a sample that skipped a field), so guard every format arg.
+	local cpuSub = (cpu and cpu.usagePercent ~= nil) and string.format("%.0f%%", cpu.usagePercent) or "—"
+	local ramSub = "—"
+	if ram and ram.usedMb ~= nil and ram.totalMb ~= nil then
+		ramSub = string.format("%.0f/%.0fM", ram.usedMb, ram.totalMb)
+	end
+
+	return ui.column({ gap = 4, fill = "surface_variant/0.35", radius = 10, paddingV = 8, paddingH = 10 }, {
+		statBar("CPU", "cpu", cpu and cpu.usagePercent, cpuSub),
+		statBar("RAM", "memory", ram and ram.usagePercent, ramSub),
+		ui.row({ gap = 12, align = "center" }, {
+			statBar("SWAP", "archive", swapPct, swapSub),
+			ui.label({ text = tr("panel.load") .. ": " .. loadSub, fontSize = 11, color = "on_surface_variant", flexGrow = 1 }),
+		}),
+	})
+end
+
+-- ── process rows ────────────────────────────────────────────────────────────
+
+-- Column layout, shared by header and data rows so they line up.
+-- { flexGrow, textAlign } for each column; cmd is the wide flexible one.
+local COLS = {
+	{ 1.0, "end" }, -- PID
+	{ 1.0, "end" }, -- CPU
+	{ 1.0, "end" }, -- MEM
+	{ 1.2, "end" }, -- RSS
+	{ 0.7, "center" }, -- STAT
+	{ 5.0, "start" }, -- COMMAND
+}
+
+-- ui.select drives sorting. Order must match the settings.sort_by options.
+local SORT_KEYS = { "cpu", "mem", "pid", "cmd" }
+local function sortIndex(key)
+	for i, k in ipairs(SORT_KEYS) do
+		if k == key then
+			return i - 1
+		end
+	end
+	return 0
+end
+
+local function toggleCpuUnit()
+	cpuUnit = cpuUnit == "pct" and "raw" or "pct"
+	render()
+end
+
+local function toggleMemUnit()
+	memUnit = memUnit == "pct" and "raw" or "pct"
+	render()
+end
+
+local function dataRow(p)
+	local stat = p.stat or "?"
+	local statColor = stat:find("Z") and "error" or "on_surface"
+	local memCell = memUnit == "raw" and fmtMem(p.rssMb) or string.format("%.1f", p.mem)
+	local cpuCell = cpuUnit == "raw" and (p.cpuTime or "—") or string.format("%.1f", p.cpu)
+	local cells = {
+		{ tostring(p.pid) },
+		{ cpuCell },
+		{ memCell },
+		{ fmtMem(p.rssMb) },
+		{ stat, statColor },
+	}
+
+	local children = {}
+	for i, c in ipairs(cells) do
+		table.insert(children, ui.label({
+			text = c[1],
+			flexGrow = COLS[i][1],
+			textAlign = COLS[i][2],
+			fontSize = 11,
+			maxLines = 1,
+			color = c[2] or "on_surface",
+		}))
+	end
+
+	-- COMMAND column (flexGrow wide)
+	table.insert(children, ui.label({
+		text = trunc(p.cmd or "?", 80),
+		flexGrow = COLS[6][1],
+		textAlign = "start",
+		fontSize = 11,
+		maxLines = 1,
+	}))
+
+	-- Kill button (fixed trailing width)
+	table.insert(children, ui.button({
+		glyph = "square-x",
+		glyphSize = 14,
+		variant = "ghost",
+		controlSize = "sm",
+		width = KILL_W,
+		tooltip = tr("panel.kill_tip", { pid = p.pid }),
+		onClick = function()
+			killPid(p.pid)
+		end,
+	}))
+
+	return ui.row({ key = tostring(p.pid), gap = 6, align = "center" }, children)
+end
+
+-- Header: clickable cells use ui.row onClick (keeps layout, so the grid stays
+-- aligned with the data rows). CPU/MEM headers toggle their column's display
+-- unit (% vs actual). Built fresh on every render so titles track the mode.
+local HEADER_LABELS = { "panel.col.pid", "panel.col.cpu", "panel.col.mem", "panel.col.rss", "panel.col.stat", "panel.col.cmd" }
+local function buildHeader()
+	local children = {}
+	for i, col in ipairs(COLS) do
+		local label = {
+			text = tr(HEADER_LABELS[i]),
+			fontSize = 11,
+			maxLines = 1,
+			color = "on_surface_variant",
+		}
+		if i == 2 then -- %CPU header toggles percent vs raw
+			label.text = cpuUnit == "raw" and tr("panel.col.cpu_raw") or tr("panel.col.cpu")
+			children[#children + 1] = ui.row({
+				flexGrow = col[1],
+				align = "center",
+				justify = col[2],
+				onClick = toggleCpuUnit,
+			}, { ui.label(label) })
+		elseif i == 3 then -- %MEM header toggles percent vs MB
+			label.text = memUnit == "raw" and tr("panel.col.mem_raw") or tr("panel.col.mem")
+			children[#children + 1] = ui.row({
+				flexGrow = col[1],
+				align = "center",
+				justify = col[2],
+				onClick = toggleMemUnit,
+			}, { ui.label(label) })
+		else
+			label.flexGrow = col[1]
+			label.textAlign = col[2]
+			children[#children + 1] = ui.label(label)
+		end
+	end
+	-- trailing spacer matching the kill column
+	children[#children + 1] = ui.spacer({ width = KILL_W })
+	return children
+end
+
+-- ── main render ─────────────────────────────────────────────────────────────
+
+function render()
+	local procs = st("procs") or {}
+	local f = filter:lower()
+
+	local list = {}
+	for _, p in ipairs(procs) do
+		if f ~= "" then
+			local cmd = (p.cmd or ""):lower()
+			local user = (p.user or ""):lower()
+			local pid = tostring(p.pid)
+			if not (cmd:find(f, 1, true) or user:find(f, 1, true) or pid:find(f, 1, true)) then
+				continue
+			end
+		end
+		table.insert(list, p)
+	end
+
+	table.sort(list, function(a, b)
+		local av, bv
+		if sortKey == "pid" then
+			av, bv = a.pid, b.pid
+		elseif sortKey == "mem" then
+			av, bv = a.mem, b.mem
+		elseif sortKey == "rss" then
+			av, bv = a.rssMb, b.rssMb
+		elseif sortKey == "cmd" then
+			av, bv = (a.cmd or ""), (b.cmd or "")
+		else
+			av, bv = a.cpu, b.cpu
+		end
+		if av == bv then
+			return a.pid < b.pid
+		end
+		if sortDir == "asc" then
+			return av < bv
+		end
+		return av > bv
+	end)
+
+	-- Bound the rendered rows so a 500-process box stays responsive.
+	local shown = list
+	if #list > MAX_ROWS then
+		shown = {}
+		for i = 1, MAX_ROWS do
+			shown[i] = list[i]
+		end
+	end
+
+	local body
+	if #shown == 0 then
+		body = ui.row({ align = "center", justify = "center", flexGrow = 1 }, {
+			ui.label({ text = tr("panel.no_processes"), color = "on_surface_variant" }),
+		})
+	else
+		local itemRows = {}
+		for _, p in ipairs(shown) do
+			table.insert(itemRows, dataRow(p))
+		end
+		body = ui.scroll({ flexGrow = 1, gap = 2, align = "stretch" }, itemRows)
+	end
+
+	local refreshedAt = (st("refreshedAtMs") or 0) / 1000
+	local refreshedStr = refreshedAt > 0 and os.date("%H:%M:%S", refreshedAt) or "—"
+	local err = st("err")
+
+	panel.render(ui.column({ padding = 12, gap = 8, flexGrow = 1, align = "stretch" }, {
+		ui.row({ align = "center", justify = "space_between" }, {
+			ui.label({ text = tr("panel.title"), fontSize = 15, fontWeight = "bold" }),
+			ui.label({ text = tr("panel.refreshed_at", { time = refreshedStr }), fontSize = 11, color = "on_surface_variant" }),
+		}),
+		renderStats(),
+		ui.row({ gap = 6, align = "center" }, {
+			ui.input({
+				key = "filter",
+				value = filter,
+				placeholder = tr("panel.search_placeholder"),
+				controlSize = "sm",
+				flexGrow = 1,
+				onChange = function(v)
+					filter = v
+					render()
+				end,
+			}),
+			ui.select({
+				options = {
+					tr("settings.sort_by.options.cpu"),
+					tr("settings.sort_by.options.mem"),
+					tr("settings.sort_by.options.pid"),
+					tr("settings.sort_by.options.cmd"),
+				},
+				selectedIndex = sortIndex(sortKey),
+				width = 110,
+				controlSize = "sm",
+				onChange = function(idx)
+					sortKey = SORT_KEYS[idx + 1]
+					render()
+				end,
+			}),
+			ui.button({
+				glyph = sortDir == "asc" and "arrow-up" or "arrow-down",
+				tooltip = sortDir == "asc" and tr("panel.sort_asc") or tr("panel.sort_desc"),
+				controlSize = "sm",
+				variant = "ghost",
+				onClick = function()
+					sortDir = sortDir == "asc" and "desc" or "asc"
+					render()
+				end,
+			}),
+		}),
+		ui.row({ gap = 6, align = "center" }, buildHeader()),
+		body,
+		ui.row({ gap = 10, align = "center" }, {
+			ui.label({ text = tr("panel.count", { n = #list }), fontSize = 11, color = "on_surface_variant" }),
+			ui.row({ gap = 8, align = "center", flexGrow = 1 }, {
+				ui.label({ text = tr("panel.refresh"), fontSize = 11, color = "on_surface_variant" }),
+				ui.slider({
+					min = 500, max = 5000, step = 500, value = math.max(500, math.min(5000, refreshMs())),
+					flexGrow = 1, controlSize = "sm",
+					onChange = function(v) refreshDraft = math.floor(tonumber(v) or 0) end,
+					onDragEnd = commitRefresh,
+				}),
+				ui.label({ text = refreshMs() .. "ms", fontSize = 11, textAlign = "end", width = 48 }),
+			}),
+			ui.label({ text = err, fontSize = 11, color = "error" }),
+		}),
+		}))
+		lastSig = signature()
+	end
+
+-- Data-driven render: only rebuild when the visible data actually changed AND
+-- enough time has passed since the last rebuild. Defined after render/signature
+-- (Luau: forward refs to a later local compile as globals -> nil).
+local function maybeRender()
+	local now = noctalia.nowMs()
+	if now - lastRenderMs < MIN_RENDER_MS then
+		return
+	end
+	if signature() ~= lastSig then
+		lastRenderMs = now
+		render()
+	end
+end
+
+noctalia.state.watch("procs", maybeRender)
+noctalia.state.watch("stats", maybeRender)
+noctalia.state.watch("refreshedAtMs", maybeRender)
+noctalia.state.watch("err", maybeRender)
+noctalia.state.watch("refreshMs", function()
+	-- Track the fetch speed on the panel's own tick so the table stays live when
+	-- the user drops the interval below the 1s second-tick floor.
+	noctalia.setUpdateInterval(refreshMs())
+	render()
+end)
+
+-- Periodic re-render on the panel tick (anilist/nix-monitor pattern). Belt and
+-- suspenders on top of state.watch: even if a cross-entry watch is missed in
+-- some shell versions, the list refreshes on its own. Track the service refresh
+-- interval so the panel keeps up when the user drops it for more real-time
+-- updates. setWantsSecondTicks is safe at this API level (9router/mawaqit use it
+-- at plugin_api 3).
+noctalia.setUpdateInterval(refreshMs())
+panel.setWantsSecondTicks(true)
+
+function update()
+	maybeRender()
+end
+
+function onOpen(_context)
+	sortKey = cfg("sort_by") or "cpu"
+	sortDir = "desc"
+	filter = ""
+	render()
+end
@@ -0,0 +1,77 @@
+id = "weinguyen/procmon"
+name = "Process Monitor"
+version = "0.3.0"
+plugin_api = 12
+author = "weinguyen"
+license = "MIT"
+icon = "cpu"
+description = "A bottom-style process monitor: live CPU/RAM/swap bars and a sortable, searchable process table with per-process kill."
+tags = ["bar", "panel", "service", "system", "utility"]
+dependencies = ["ps", "kill", "head", "grep", "cat"]
+
+[[setting]]
+key = "refresh_interval"
+type = "int"
+label_key = "settings.refresh_interval.label"
+description_key = "settings.refresh_interval.description"
+default = 1000
+min = 250
+max = 30000
+
+[[setting]]
+key = "sort_by"
+type = "select"
+label_key = "settings.sort_by.label"
+description_key = "settings.sort_by.description"
+default = "cpu"
+options = [
+  { value = "cpu", label_key = "settings.sort_by.options.cpu" },
+  { value = "mem", label_key = "settings.sort_by.options.mem" },
+  { value = "pid", label_key = "settings.sort_by.options.pid" },
+  { value = "cmd", label_key = "settings.sort_by.options.cmd" },
+]
+
+[[setting]]
+key = "kill_command"
+type = "string"
+label_key = "settings.kill_command.label"
+description_key = "settings.kill_command.description"
+default = "kill -TERM"
+
+[[widget]]
+id = "widget"
+entry = "widget.luau"
+
+  [[widget.setting]]
+  key = "glyph"
+  type = "glyph"
+  label_key = "settings.glyph.label"
+  description_key = "settings.glyph.description"
+  default = "cpu"
+
+  [[widget.setting]]
+  key = "show_count"
+  type = "bool"
+  label_key = "settings.show_count.label"
+  description_key = "settings.show_count.description"
+  default = true
+
+  [[widget.setting]]
+  key = "icon_only"
+  type = "bool"
+  label_key = "settings.icon_only.label"
+  description_key = "settings.icon_only.description"
+  default = false
+
+[[panel]]
+id = "panel"
+entry = "panel.luau"
+width = 620
+height = 660
+placement = "floating"
+position = "center"
+open_near_click = true
+
+[[service]]
+id = "service"
+entry = "service.luau"
@@ -0,0 +1,251 @@
+--!nonstrict
+-- Process Monitor — background sampler (service).
+--
+-- Runs `ps` every refresh_interval ms, parses the rows, and publishes the
+-- process list plus a lightweight CPU/RAM summary through the plugin state
+-- channel. The bar widget and panel are pure subscribers.
+--
+-- Structure matches the proven audio-switcher/drive-health service pattern:
+--   noctalia.setUpdateInterval(...) + function update() + a guarded runAsync.
+--
+-- Root-cause hardening (added 0.1.5):
+--   * Every step logs via noctalia.log so runtime failures are visible in the
+--     shell's plugin log instead of the silent "service stopped responding".
+--   * The runAsync callback body runs under pcall: an internal error can no
+--     longer take the service VM down and trip the watchdog; it logs instead.
+--   * refreshedAtMs uses os.time()*1000 (milliseconds) so the sampler has no
+--     dependency on noctalia.nowMs().
+--   * stats is derived from the ps output itself (summed %cpu/%mem/rss), so the
+--     bars work without noctalia.systemStats().
+
+local function cfg(key)
+	return noctalia.getConfig(key)
+end
+
+local function setState(key, val)
+	noctalia.state.set(key, val)
+end
+
+local function st(key)
+	return noctalia.state.get(key)
+end
+
+local function log(msg)
+	noctalia.log("[procmon/service] " .. msg)
+end
+
+-- `args` is placed last so the fixed fields are positional and everything
+-- after them is the full command line (which may contain spaces). The shell
+-- pre-sorts by CPU and truncates to the top 120 rows so the Luau parse stays
+-- tiny: parsing every process blew the async callback's CPU budget even with a
+-- single-pass gmatch. btm shows a screenful anyway, so top-120 is plenty.
+-- The trailing ##STAT/##MEM sections carry real total CPU/RAM from /proc so the
+-- bars read the machine's actual usage -- ps %cpu is a per-process lifetime
+-- average, so summing the top rows and capping at 100 always pegged the bar.
+local PS_CMD = "ps -eo pid=,user=,%cpu=,%mem=,rss=,stat=,time=,args= --sort=-%cpu | head -n 120"
+
+-- Real total CPU/RAM come from /proc in a SEPARATE, tiny command so the async
+-- callback that parses it stays far under the CPU budget. Folding the markers
+-- into the ps command made one callback scan the whole ~15KB buffer two extra
+-- times (string.match over the full output) and tipped it over the razor-thin
+-- budget. Each callback now parses only its own small output.
+local STATS_CMD = "grep '^cpu ' /proc/stat; echo '##MEM'; grep -E 'MemTotal:|MemAvailable:|SwapTotal:|SwapFree:' /proc/meminfo; echo '##LOAD'; cat /proc/loadavg"
+
+-- Single-pass row pattern. ps -eo with trailing `=` emits no header. Six
+-- space-delimited fields then `([^\n]*)` grabs the rest of the line (args, which
+-- may contain spaces). Note: `.*` would cross newlines in Lua (dot matches `\n`),
+-- collapsing every remaining row into the first one -- so args must be `[^\n]*`.
+-- One gmatch pass, no per-token tables, no trim gsubs. ppid/etime are dropped
+-- (not shown in the panel) to keep captures to a minimum for the CPU budget.
+local ROW = "(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+([^\n]*)"
+
+-- Upper bound on how long `ps` may take before we give up on a sample.
+local PS_TIMEOUT_MS = 5000
+
+local function parse(raw)
+	local list, n = {}, 0
+	for pidS, user, cpuS, memS, rssS, stat, timeS, args in raw:gmatch(ROW) do
+		local pid = tonumber(pidS)
+		if pid ~= nil then
+			n += 1
+			list[n] = {
+				pid = pid,
+				user = user,
+				cpu = tonumber(cpuS) or 0,
+				mem = tonumber(memS) or 0,
+				rssMb = (tonumber(rssS) or 0) / 1024,
+				stat = stat,
+				cpuTime = timeS or "0:00",
+				cmd = args,
+			}
+		end
+	end
+	return list
+end
+
+-- Real total CPU% from /proc/stat deltas between consecutive samples. ps %cpu is
+-- a lifetime average, so we diff the kernel's cumulative jiffies instead.
+local prevCpu = nil -- { busy, total }
+
+local function sampleCpu(raw)
+	local line = raw:match("^cpu%s+([^\n]+)")
+	if not line then
+		return nil
+	end
+	local t = {}
+	for n in line:gmatch("%d+") do
+		t[#t + 1] = tonumber(n)
+	end
+	if #t < 4 then
+		return nil
+	end
+	-- cpu user nice system idle iowait irq softirq steal ... ; idle=iowait=0 load.
+	local total, busy = 0, 0
+	for i = 1, 8 do
+		local v = t[i] or 0
+		total += v
+		if i ~= 4 and i ~= 5 then
+			busy += v
+		end
+	end
+	if not prevCpu then
+		prevCpu = { busy = busy, total = total }
+		return nil -- need one more sample to diff
+	end
+	local db = busy - prevCpu.busy
+	local dt = total - prevCpu.total
+	prevCpu = { busy = busy, total = total }
+	if dt <= 0 then
+		return 0
+	end
+	local pct = db / dt * 100
+	if pct < 0 then
+		pct = 0
+	elseif pct > 100 then
+		pct = 100
+	end
+	return math.floor(pct + 0.5)
+end
+
+local function sampleSwap(raw)
+	local sec = raw:match("##MEM\n(.+)") or ""
+	local totalKb = tonumber(sec:match("SwapTotal:%s*(%d+)") or "")
+	if not totalKb or totalKb <= 0 then
+		return nil
+	end
+	local freeKb = tonumber(sec:match("SwapFree:%s*(%d+)") or "")
+	local usedKb = totalKb - (freeKb or 0)
+	if usedKb < 0 then
+		usedKb = 0
+	end
+	return math.floor(usedKb / totalKb * 100 + 0.5), math.floor(usedKb / 1024), math.floor(totalKb / 1024)
+end
+
+-- Load average (1/5/15 min) from /proc/loadavg.
+local function sampleLoad(raw)
+	local line = raw:match("##LOAD\n([^\n]+)")
+	if not line then
+		return nil
+	end
+	local a = {}
+	for n in line:gmatch("%d+%.%d+") do
+		a[#a + 1] = tonumber(n)
+	end
+	if #a >= 3 then
+		return { a[1], a[2], a[3] }
+	end
+	return nil
+end
+local function sampleRam(raw)
+	local sec = raw:match("##MEM\n(.+)") or ""
+	local totalKb = tonumber(sec:match("MemTotal:%s*(%d+)") or "")
+	local availKb = tonumber(sec:match("MemAvailable:%s*(%d+)") or "")
+	if not totalKb or not availKb or totalKb <= 0 then
+		return nil
+	end
+	local usedKb = totalKb - availKb
+	if usedKb < 0 then
+		usedKb = 0
+	end
+	return math.floor(usedKb / totalKb * 100 + 0.5), math.floor(usedKb / 1024), math.floor(totalKb / 1024)
+end
+
+local sampling = false
+
+local function sample()
+	if sampling then
+		return -- one in-flight sample at a time
+	end
+	sampling = true
+
+	noctalia.runAsync(PS_CMD, function(res)
+		local ok, perr = pcall(function()
+			sampling = false
+			if res == nil or res.timedOut or res.exitCode ~= 0 then
+				local detail = res and (res.stderr or res.stdout or "") or "no result"
+				setState("err", detail)
+				return
+			end
+			local procs = parse(res.stdout)
+			setState("procs", procs)
+			setState("refreshedAtMs", os.time() * 1000)
+		end)
+		if not ok then
+			sampling = false
+			log("ps callback error: " .. tostring(perr))
+		end
+	end, PS_TIMEOUT_MS)
+
+	noctalia.runAsync(STATS_CMD, function(res)
+		local ok, perr = pcall(function()
+			sampling = false
+			if res == nil or res.timedOut or res.exitCode ~= 0 then
+				return
+			end
+			local cpuPct = sampleCpu(res.stdout)
+			local ramPct, usedMb, totalMb = sampleRam(res.stdout)
+			local swapPct, swapUsedMb, swapTotalMb = sampleSwap(res.stdout)
+			local loadAvg = sampleLoad(res.stdout)
+			setState("stats", {
+				cpu = { usagePercent = cpuPct or 0 },
+				ram = { usagePercent = ramPct or 0, usedMb = usedMb or 0, totalMb = totalMb or 0 },
+				swap = { usagePercent = swapPct or 0, usedMb = swapUsedMb or 0, totalMb = swapTotalMb or 0 },
+				loadAvg = loadAvg or { 0, 0, 0 },
+			})
+			setState("err", "")
+		end)
+		if not ok then
+			sampling = false
+			log("stats callback error: " .. tostring(perr))
+		end
+	end, PS_TIMEOUT_MS)
+end
+
+-- Seed placeholders so subscribers have something before the first sample.
+setState("procs", {})
+setState("stats", { cpu = { usagePercent = 0 }, ram = { usagePercent = 0, usedMb = 0, totalMb = 0 } })
+setState("refreshedAtMs", 0)
+setState("err", "")
+
+local function refreshInterval()
+	return tonumber(st("refreshMs") or cfg("refresh_interval")) or 1000
+end
+
+-- The panel's Refresh slider publishes its value here; re-arming the sampler
+-- timer is how the fetch speed actually changes. Seeded from config so a
+-- reload falls back to the user's saved setting.
+setState("refreshMs", cfg("refresh_interval") or 1000)
+noctalia.state.watch("refreshMs", function(v)
+	local n = tonumber(v)
+	if n and n > 0 then
+		noctalia.setUpdateInterval(n)
+		log("interval=" .. n)
+	end
+end)
+
+noctalia.setUpdateInterval(refreshInterval())
+log("loaded, interval=" .. refreshInterval())
+
+function update()
+	sample()
+end
@@ -0,0 +1,59 @@
+{
+  "settings": {
+    "refresh_interval": {
+      "label": "Refresh interval (ms)",
+      "description": "How often the process list is resampled."
+    },
+    "sort_by": {
+      "label": "Default sort column",
+      "description": "Column the process table is sorted by when the panel opens.",
+      "options": {
+        "cpu": "CPU",
+        "mem": "Memory",
+        "pid": "PID",
+        "cmd": "Command"
+      }
+    },
+    "kill_command": {
+      "label": "Kill command",
+      "description": "Command run against a selected PID (the PID is appended). Empty uses kill -TERM."
+    },
+    "show_count": {
+      "label": "Show process count",
+      "description": "Append the number of processes to the bar widget text."
+    },
+    "glyph": {
+      "label": "Widget icon",
+      "description": "Glyph shown in the bar widget."
+    },
+    "icon_only": {
+      "label": "Icon only",
+      "description": "Show only a CPU icon in the bar widget; details move to the tooltip."
+    }
+  },
+  "widget": {
+    "tooltip": "CPU {cpu}%  RAM {ram}%  ·  {n} processes"
+  },
+  "panel": {
+    "title": "Processes",
+    "refreshed_at": "Updated {time}",
+    "refresh": "Refresh",
+    "load": "Load",
+    "search_placeholder": "Filter by name, user or PID",
+    "sort_asc": "asc",
+    "sort_desc": "desc",
+    "col": {
+      "pid": "PID",
+      "cpu": "CPU%",
+      "cpu_raw": "CPU",
+      "mem": "MEM%",
+      "mem_raw": "MEM",
+      "rss": "RSS",
+      "stat": "S",
+      "cmd": "COMMAND"
+    },
+    "count": "{n} processes",
+    "no_processes": "No matching processes",
+    "kill_tip": "Kill {pid}"
+  }
+}
@@ -0,0 +1,56 @@
+--!nonstrict
+-- Process Monitor — bar widget. Full mode shows "CPU% RAM% · count" text; icon-only
+-- mode shows just a CPU icon colored by load, with the details in the tooltip so the
+-- bar stays tiny. Clicking opens the panel.
+
+local function cfg(key)
+	return noctalia.getConfig(key)
+end
+
+local function st(key)
+	return noctalia.state.get(key)
+end
+
+local function tr(key, subst)
+	return noctalia.tr(key, subst)
+end
+
+function update()
+	local stats = st("stats")
+	local cpu = stats and stats.cpu and stats.cpu.usagePercent
+	local ram = stats and stats.ram and stats.ram.usagePercent
+	local count = #(st("procs") or {})
+	local cpuInt = math.floor(cpu or 0)
+	local tooltip = tr("widget.tooltip", { cpu = cpuInt, ram = math.floor(ram or 0), n = count })
+
+	barWidget.setGlyph(cfg("glyph") or "cpu")
+	barWidget.setTooltip(tooltip)
+
+	if cfg("icon_only") then
+		barWidget.setText("")
+		-- color the icon by CPU load so a glance reads the machine state
+		if cpuInt >= 80 then
+			barWidget.setGlyphColor("error")
+		elseif cpuInt >= 50 then
+			barWidget.setGlyphColor("warning")
+		else
+			barWidget.setGlyphColor("on_surface")
+		end
+		return
+	end
+
+	barWidget.setGlyphColor("on_surface")
+	local text = string.format("CPU %d%%  RAM %d%%", cpuInt, math.floor(ram or 0))
+	if cfg("show_count") then
+		text = text .. "  ·  " .. count
+	end
+	barWidget.setText(text)
+end
+
+noctalia.state.watch("stats", update)
+noctalia.state.watch("procs", update)
+noctalia.setUpdateInterval(1000)
+
+function onClick()
+	noctalia.togglePanel("weinguyen/procmon:panel")
+end