print-file

Local file printing

Use cases

Use this skill when the user asks to print a local file, a just-generated file, a PDF, an image, or a document.

Core rules

• Before each print, you must confirm with the user:
  • Paper size, default A4
  • Print color, default 黑白
• If the user has already clearly specified the paper and color in the same sentence, you may skip asking again.
• Do not submit a print job directly without confirming the paper and color.
• Before printing, first confirm that the file actually exists.
• Prefer the system default printer; if there is no default printer, list the available printers and let the user choose.
• If lpstat cannot find a printer in the sandbox, retry with escalated permissions; this is usually restricted access to the macOS printing service and does not mean there is no printer.

Standard process

1. Locate the file:

ls -lh "<file>"

1. Query the printer:

lpstat -d
lpstat -e
lpstat -p

1. Query the paper and color options supported by the target printer:

lpoptions -p "<printer>" -l

1. Confirm the settings with the user. Recommended phrasing:

准备打印 <file> 到 <printer>。纸张用 A4、黑白打印，可以吗？

If the user wants to change them, accept common values:

User wording	Common CUPS values
A4	A4
A5	A5
Letter	Letter
Black and white / grayscale	Gray or monochrome
Color	RGB or color

1. Submit the print job.

Prefer generic CUPS options:

lp -d "<printer>" -o media=A4 -o ColorModel=Gray "<file>"

If the printer does not support ColorModel=Gray, based on the output of lpoptions -p "<printer>" -l , switch to the actual options, for example:

lp -d "<printer>" -o media=A4 -o print-color-mode=monochrome "<file>"
lp -d "<printer>" -o media=A4 -o cupsPrintQuality=Draft "<file>"

1. Report the job number and check the queue:

lpstat -W not-completed -o "<printer>"
lpstat -p "<printer>" -l

Reprint

If the user says "do it again/reprint/print another copy", check the queue first:

lpstat -W not-completed -o "<printer>"

• If the old job is still in the queue, first ask whether to cancel the old job to avoid duplicate printing.
• If the user clearly indicates that the old job failed, is being retried after running out of paper, or is stuck, cancel the old job and resubmit:

cancel "<job-id>"
lp -d "<printer>" -o media=A4 -o ColorModel=Gray "<file>"

Troubleshooting

• Hardware states such as red lights, out of paper, paper jams, and low ink can usually only be handled by the user on the printer; the CLI can only see the queue status.
• lpstat shows the job staying in not-completed: prompt the user to check the paper, paper jams, ink, printer power, and USB/Wi-Fi connection.
• When the printer is offline or paused, report the status first; do not repeatedly submit multiple jobs.
• If the user reloads paper and wants to print again: cancel the stuck old job, then submit a new job.

Common command quick reference

lpstat -d                              # 默认打印机
lpstat -e                              # 打印机名称列表
lpstat -p                              # 打印机状态
lpoptions -p "<printer>" -l            # 支持的纸张/颜色/质量选项
lp -d "<printer>" -o media=A4 -o ColorModel=Gray "<file>"
lpstat -W not-completed -o "<printer>" # 未完成任务
cancel "<job-id>"                      # 取消任务