Printers

Your CUPS printers and print queue in the Noctalia bar. The widget stays out of the way until a job is queued or a printer stops, and the panel lets you set the default printer, cancel jobs, print the clipboard and open the CUPS web interface.

Everything is discovered from lpstat at runtime, so there is nothing to configure: whatever destinations CUPS knows about are the ones you see.

Plugin

Field	Value
ID	andrewdems/printers
Entries	Bar widget: printer; panel: panel; service: service; shortcut: toggle

Requirements

A running CUPS installation providing lpstat, lp, cancel, lpoptions, lpinfo and lpadmin on PATH (the cups package on most distributions), plus xdg-open for the Open CUPS button.

Adding and removing printers needs CUPS administrative rights. On a normal desktop install your user is already in the CUPS SystemGroup (sys or wheel depending on the distribution) and lpadmin works with no password; if it does not, the panel reports what CUPS said instead of prompting.

The Printer settings button runs whatever settings_command names (system-config-printer by default). Install it, point the setting at another tool, or ignore the button.

Usage

Add the Printers widget under Settings → Bar (or put andrewdems/printers:printer in a bar's widget list in config.toml). By default it appears only when there is a job in the queue or a printer has stopped; turn on Always show the bar widget to keep it pinned. The glyph turns red and switches to a struck-through printer when a destination reports itself disabled, and the job count sits next to it.

Click the widget to open the panel, right-click it to re-poll immediately. The toggle shortcut can be added to the Control Center from Settings → Control Center; it opens the same panel.

In the panel:

• Printers: every CUPS destination with its state. The default is shown in bold; Set default on any other row runs lpoptions -d, and the trash icon removes the queue after a confirmation step. A driverless printer that CUPS has discovered but not yet added shows as available, not yet added, and can be set as the default like any other.
• Queue: the active jobs, newest CUPS order. Each row carries the job's CUPS status, so a job stuck in the filter chain says why on the row instead of failing silently; a failed job turns the row red and the bar widget with it. The × on a row cancels that job; Cancel all asks for confirmation, then cancels the lot.
• Add a printer: expand it to list what CUPS can see over DNS-SD, IPP, USB, LPD and raw sockets. Each printer is listed once, preferring its driverless IPP service over the raw port, and shows the queue name it would get. Add creates it with lpadmin -m everywhere, so the queue is driverless IPP Everywhere with no vendor driver and no PPD to maintain. A device that is already a queue says so and cannot be added twice; the match is on the device URI, not the name, so a queue set up by another tool is still recognised.
• Open CUPS opens the CUPS web interface, Printer settings launches your printer configuration tool, and Print clipboard sends the current clipboard text to the default printer.

Open or close the panel with:

noctalia msg panel-toggle andrewdems/printers:panel

Settings

Setting	Type	Default	Description
poll_interval_seconds	int	10	How often lpstat is queried (5–300 seconds).
show_when_idle	bool	false	Keep the bar widget visible with an empty queue and no fault.
notify_on_fault	bool	true	Notify the first time a printer reports itself disabled or stopped.
cups_url	string	http://localhost:631/jobs/	URL opened by Open CUPS.
settings_command	string	system-config-printer	Command run by Printer settings. Split on spaces, run directly, never through a shell.

IPC

noctalia msg plugin andrewdems/printers:service all refresh          # re-poll now
noctalia msg plugin andrewdems/printers:service all status           # notify with the default printer and job count
noctalia msg plugin andrewdems/printers:service all cancel <job-id>  # cancel one job, e.g. Office_Laser-7
noctalia msg plugin andrewdems/printers:service all cancel-all       # cancel every job
noctalia msg plugin andrewdems/printers:service all print-clipboard  # print the clipboard on the default printer

Notes

• Processes. The service spawns lpstat -d, lpstat -p, lpstat -e and lpstat -l -o on every poll, lpstat -v and lpinfo on every poll while "Add a printer" is expanded (the discoverable-device scan is otherwise skipped, since nothing reads it with the section collapsed), and cancel, lpoptions -d, lp -d, xdg-open or the configured settings command when you use an action. Every one is spawned as an argv list, never through a shell, so a printer or job name can never be interpreted as a command.
• Files. Print clipboard writes the clipboard text to a timestamped clipboard-<ms>.txt in the plugin's data directory, passes that path to lp, and deletes it as soon as lp returns. The timestamp keeps two overlapping print requests from racing on the same file. Nothing else is written, and the text never appears on a command line.
• Network. The plugin makes no network requests of its own. cups_url is handed to xdg-open, which opens it in your browser.
• Privacy. No printer name, host or queue is stored in the plugin. Names come from lpstat at runtime and live only in the shell's memory.
• Driverless printers. Destinations come from lpstat -p (configured queues) merged with lpstat -e (everything CUPS can print to). An IPP Everywhere printer found over DNS-SD appears in the second list only until CUPS materializes a permanent queue for it, so without the merge it would be missing from the panel on exactly the setups that need no configuration. Once the queue exists, both lists name the same printer with different punctuation (HP_Smart_Tank_580_590_series announced, HP_Smart_Tank_580-590_series queued), so names are compared with punctuation and case folded and the printer is listed once.
• Printer changes. Add runs lpadmin -p <name> -E -v <uri> -m everywhere and the trash icon runs lpadmin -x <name>. Both change system-wide CUPS configuration, not just this user's, which is why removal asks first. Only driverless printers can be added here; one that needs a vendor driver has to be set up in a full printer configuration tool.
• Faults. A printer is treated as faulted when lpstat -p reports it as disabled or stopped, and a job is treated as failed when its CUPS alert mentions an error. CUPS keeps that state until you re-enable the printer, so the widget stays red until the underlying problem is cleared.

AI assistance

This plugin, and this README, were written with AI assistance. I run it on my own desktop and tested what shipped.