acpi_available command in Linux with examples

acpi_available is a command in Linux which test whether ACPI (Advanced Configuration and Power Interface) subsystem is available or not. It has three return statuses:

• 0 : It means ACPI subsystem is available.
• 1 : It means ACPI subsystem is not available.
• 2 : It means some usage error has occurred.

Syntax:

$ acpi_available

Example 1: Here, echo $? is a command which is used to see the last return status. Example 2: Here, we create a false error and then displayed return status. Options: 

• info acpi_available : It displays help information. Example: