nproc: Print the number of available processors
Print the number of processing units available to the current process,
which may be less than the number of online processors.
If this information is not accessible, then print the number of
processors installed. If the
environment variables are set, then they will determine the minimum
and maximum returned value respectively. The result is guaranteed to be
greater than zero. Synopsis:
The program accepts the following options. Also see Common options.
Print the number of installed processors on the system, which may
be greater than the number online or available to the current process.
OMP_THREAD_LIMIT environment variables
are not honored in this case.
If possible, exclude this number of processing units.
An exit status of zero indicates success, and a nonzero value indicates failure.