Test whether apm subsystem is available
apm_available checks whether the APM ("Advanced Power Management") subsystem is available, as evidenced by the presence of the /proc/apm file.
0 (true) APM subsystem is available 1 (false) APM subsystem is not available 2 usage error (arguments supplied)
/proc/apm APM status information file
This manual page was written by Thomas Hood <[email protected]>.