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
OMP_NUM_THREADS environment variable is
set, then it will determine the returned value. 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_NUM_THREADS environment variable is 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.