hp-levels

hp-levels [OPTIONS]

-i, --info
    Displays general information about the hp-levels utility itself.

-g, --gui
    Launches a graphical user interface (GUI) for checking HP printer levels, providing a more visual representation of cartridge status.

-d level, --debug level
    Enables debug mode with a specified numerical level (e.g., 1-10). This provides verbose output, which is highly useful for troubleshooting communication issues or understanding the command's internal operations.

-h, --help
    Displays a help message detailing the command's usage and available options.

The hp-levels command is a crucial utility within the HPLIP (HP Linux Imaging and Printing) software suite, designed specifically for managing HP printers on Linux systems. Its primary function is to provide users with a quick and convenient way to monitor the ink or toner cartridge levels of their connected HP printers directly from the command line. This tool queries the printer for its supply levels and displays them, often indicating percentages for black and color cartridges, or a general status like "OK" or "Low".

It's particularly useful for users who prefer command-line interfaces or for scripting purposes where graphical tools might be cumbersome. hp-levels helps users anticipate when cartridges need replacement, preventing unexpected interruptions during printing tasks.

• Requires the HPLIP (HP Linux Imaging and Printing) software package to be installed and properly configured for your HP printer.
• The printer must be powered on and actively connected to the system (via USB or network) for hp-levels to communicate with it.
• Not all HP printer models may report precise ink/toner levels, or some older models might not be fully supported by the utility, potentially showing generic statuses like "Unknown" or "OK".
• For network printers, proper network connectivity and firewall configurations are essential for detection and status retrieval.
• The accuracy of reported levels can sometimes vary depending on the printer's firmware and communication protocol.

hp-levels communicates directly with the HP printer, typically utilizing protocols such as SNMP (Simple Network Management Protocol) for network-connected printers or device-specific USB protocols for locally connected printers. It queries the printer's internal status registers to retrieve information about the ink or toner levels. The reported levels are usually presented as percentages, but can sometimes be simpler status indicators (e.g., "OK", "Low", "Empty") depending on the printer's capabilities and the information it exposes.

To check levels for a printer, simply running `hp-levels` will attempt to detect and display information for connected HP printers. If multiple HP printers are configured, it might list them or focus on the default one. For more detailed troubleshooting or to understand the communication process, combining it with the `-d` (debug) option can provide valuable insights into the interaction between the command and the printer.

The hp-levels command is an integral part of the HPLIP (HP Linux Imaging and Printing) project, which was initiated by HP in 2000 to provide comprehensive Linux support for its printing and imaging devices. Developed as open-source software, HPLIP aims to ensure that HP printers, all-in-ones, and fax machines function seamlessly on Linux distributions. hp-levels was developed as a key utility within this suite to address the common user need of monitoring consumable levels, evolving alongside the broader HPLIP project to support new printer models and communication protocols. Its development has focused on robustness and ease of use, leveraging various printer communication methods (like SNMP for network printers or USB protocols) to retrieve cartridge status.

hp-setup(1), hp-check(1), hp-info(1), hp-doctor(1), lpstat(1)