The following script displays the number of cores available in the system.

  #!/bin/sh
  echo "Bash version ${BASH_VERSION}..."

  cores=$(grep -c ^processor /proc/cpuinfo 2>/dev/null || sysctl -n hw.ncpu)
  echo "Number of cores in the system : ${cores}"
  ((coresusable=cores-1))
  echo However, only "$coresusable" should be used
  echo ""

  if (eval "$@") >&/dev/null; then
        perl -e 'printf "\033[30;102m[ OK ]\033[0m @ARGV\n"' "$@"
      else
        perl -e 'printf "\033[30;101m[FAIL]\033[0m @ARGV\n"' "$@"
      fi

Example:

  Bash version 3.2.57(1)-release...
  Number of cores in the system : 4
  However, only 3 should be used

  [ OK ]