hostid

The hostid command line tool is used to retrieve the unique identifier of a host machine. It is primarily used in Unix-like operating systems such as Linux and macOS.

When executed, the hostid command displays a hexadecimal number that represents the host identifier. This identifier is usually derived from the MAC address of the network interface card (NIC) on the machine.

The hostid value is often used for software licensing purposes or as a reference for identifying a specific machine in network setups.

The hostid command can be used with various options to modify its behavior. For example, the -d or --decimal option displays the hostid value in decimal instead of hexadecimal format.

Another option is -t or --tag, which displays the hostid with a machine-readable tag prefix. This can be useful for scripting or parsing the output in automated processes.

The hostid command does not require root privileges to execute, and can be run by any user on the system.

If the hostid cannot be determined, the command may display a warning or return an error code depending on the operating system.

The hostid value is typically stored in a system file, which can be accessed by the command to retrieve the identifier.

Some systems may allow changing the hostid value, but this is not recommended as it can lead to software licensing issues or disrupt network functionality.

Overall, the hostid command line tool provides a quick and easy way to retrieve the unique identifier of a host machine, aiding in various system administration tasks.