Determining CPU Cores in Bash

nproc is part of coreutils package that gives the number of cores available in an easy to consume way (no more grepping and parsing ).

I wanted this to set VECTOR_THREADS variable for vector CLI to 1/2 of what is available on system.

#!/bin/bash

set -e

cores=`nproc --all`
cap=2
VECTOR_THREADS=$((cores / cap))

vector --config /etc/vector