cupsd command in Linux with examples
cupsd is a type of scheduler for CUPS (Common Unit Printing System). It implements the printing system on the basis of the Internet Printing Protocol(Version 2.1). If no options is being specified on the command-line then the default configuration file /etc/cups/cupsd.conf will be automatically be used.
Installation of CUPS on Linux
To install the CUPS in your Linux machine, simply use the sudo command with the apt. A complete CUPS package installation has many package dependencies, but they can all be specified on the same command line. Enter the following command on the terminal:
sudo apt install cups
Once your username and password are authenticated, the packages must be downloaded and installed without error. After the installation, the CUPS server will start automatically by default.
Syntax
cupsd [ -c config-file ] [ -f ] [ -F ] [ -h ] [ -l ] [ -t ]
Key Options used with the cupsd command
Option | Description |
---|---|
cupsd -c config-file | Uses the named configuration file instead of the default /etc/cups/cupsd.conf . |
cupsd -f | Runs cupsd in the foreground. The default is to run as a background daemon. |
cupsd -F | Runs cupsd in the foreground but detaches from the controlling terminal and current directory. Useful for init . |
cupsd -h | Displays the program usage information. |
cupsd -l config-file | Used when cupsd is run from launchd or systemd with the specified configuration file. |
cupsd -t | Tests the configuration file for syntax errors without starting the daemon. |
cupsd --help | Displays the general syntax of the cupsd command along with available options and brief descriptions. |
Basic Example:
Web Interface: CUPS can be easily configured and can be monitored using a web interface, which is by default available at http://localhost:631/admin. The web interface can be used to perform all the printer management tasks.

In order to perform the administrative tasks through the web interface, you must either have the root account enabled on your server, or you need to authenticate as a user in the lpadmin group. For security reasons, CUPS by default won't authenticate a user that doesn't have a password.
To add a user to the lpadmin group, run at the following command in your terminal prompt:
sudo usermod -aG lpadmin username
cupsd command Examples
Here are a few practical examples of how to use the cupsd command:
1. Running cupsd with the default configuration file:
cupsd
2. Testing a custom configuration file:
cupsd -t -c test.conf
3. Running cupsd in the foreground with a custom configuration file:
cupsd -f -c test.conf
Conclusion
CUPS and the cupsd daemon offer a powerful way to manage printing in Unix-like systems. From installation to configuration, understanding the various options and commands available can help you take full advantage of this system. By utilizing both the command-line and web interface, you can efficiently manage printers, resolve common issues, and maintain smooth operations for your print jobs.