cancel - macOS

Overview

The cancel command in macOS is used to cancel existing print jobs on a system. It can be employed by users needing to manage or halt printing tasks that are either pending or currently in process. The command is particularly useful in environments with heavy printer usage where mistakes in print jobs are frequent or when paper or ink conservation is necessary.

Syntax

The basic syntax of the cancel command is as follows:

cancel [options] [job-id(s) | printer-name]

job-id(s): Specifies the print job ID(s) to cancel. If no job-ID or printer is specified, the command may attempt to cancel all jobs pending for the current user.
printer-name: Cancels all jobs queued to a specified printer.

Options/Flags

-a: When used, this option cancels all jobs on all printers, provided the user has the necessary permissions.
-u username: Cancels all jobs submitted by the specified user. This is typically used by administrators.
-x: This option is used to cancel all jobs regardless of the user or printer. It is a powerful tool and should be used with caution, typically only by administrators.

Note: The availability and functionality of options can vary slightly between different Unix-like systems, including variations in macOS versions.

Examples

Cancel a specific print job:
If you know the job ID:
```
cancel 105
```
This command cancels the print job with the ID 105.
Cancel all jobs on a specific printer:
```
cancel HP-Printer
```
This will cancel all pending jobs on the printer named “HP-Printer.”
Cancel all your jobs:
```
cancel -a
```
This command cancels all print jobs submitted by the current user across all printers.
Cancel all jobs by a specific user:
```
cancel -u johndoe
```
Administrators can use this to cancel all print jobs submitted by the user “johndoe.”

Common Issues

Permission Denied: Users may receive this error if they attempt to cancel jobs they did not submit, or without proper administrative rights. Ensure you have the necessary permissions or contact your system administrator.
Invalid Job/Printer ID: Users sometimes encounter this error if the job or printer ID does not exist. Double-check the IDs before attempting a cancellation.

Integration

The cancel command can be combined with other commands for more complex scripting or workflows, such as:

lpstat -p | grep 'idle' | awk '{print $2}' | xargs cancel

This script checks for printers that are idle and cancels any jobs that might be stuck in the queue.

lpstat: Used to display status information about current print jobs and printers.
lprm: Another command to remove jobs from the print queue, similar in function to cancel.

For further reading and more detailed information, users can refer to the macOS man pages by typing man cancel in the terminal.