config_cpu() {
  extinfo=""
  if grep -q '^cpu \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\}' /proc/stat; then
    extinfo="iowait irq softirq"
  fi
  # shellcheck disable=SC2126
  NCPU=$(grep '^cpu[0-9]\+ ' /proc/stat | wc -l)
  PERCENT=$((NCPU * 100))
  graphlimit=$PERCENT
  SYSWARNING=$((PERCENT * 30 / 100))
  SYSCRITICAL=$((PERCENT * 50 / 100))
  USRWARNING=$((PERCENT * 80 / 100))
  echo "graph_title CPU usage"
  echo "graph_order system user nice idle $extinfo" | sed 's/ $//'
  echo "graph_args --base 1000 -r --lower-limit 0 --upper-limit $graphlimit"
  echo "graph_vlabel %"
  echo "graph_scale no"
  echo "graph_info This graph shows how CPU time is spent."
  echo "graph_category system"
  echo "graph_period second"
  echo "system.label system"
  echo "system.draw AREA"
  echo "system.max 5000"
  echo "system.min 0"
  echo "system.type DERIVE"
  echo "system.warning $SYSWARNING"
  echo "system.critical $SYSCRITICAL"
  echo "system.info CPU time spent by the kernel in system activities"
  echo "user.label user"
  echo "user.draw STACK"
  echo "user.min 0"
  echo "user.max 5000"
  echo "user.warning $USRWARNING"
  echo "user.type DERIVE"
  echo "user.info CPU time spent by normal programs and daemons"
  echo "nice.label nice"
  echo "nice.draw STACK"
  echo "nice.min 0"
  echo "nice.max 5000"
  echo "nice.type DERIVE"
  echo "nice.info CPU time spent by nice(1)d programs"
  echo "idle.label idle"
  echo "idle.draw STACK"
  echo "idle.min 0"
  echo "idle.max 5000"
  echo "idle.type DERIVE"
  echo "idle.info Idle CPU time"
  if [ -n "$extinfo" ]; then
    echo "iowait.label iowait"
    echo "iowait.draw STACK"
    echo "iowait.min 0"
    echo "iowait.max 5000"
    echo "iowait.type DERIVE"
    echo "iowait.info CPU time spent waiting for I/O operations to finish"
    echo "irq.label irq"
    echo "irq.draw STACK"
    echo "irq.min 0"
    echo "irq.max 5000"
    echo "irq.type DERIVE"
    echo "irq.info CPU time spent handling interrupts"
    echo "softirq.label softirq"
    echo "softirq.draw STACK"
    echo "softirq.min 0"
    echo "softirq.max 5000"
    echo "softirq.type DERIVE"
    echo "softirq.info CPU time spent handling 'batched' interrupts"
  fi
}
fetch_cpu() {
  extinfo=""
  if grep -q '^cpu \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\} \{1,\}[0-9]\{1,\}' /proc/stat; then
    extinfo="iowait irq softirq"
  fi
  CINFO=$(grep '^cpu ' /proc/stat | cut -c6-)
  echo "user.value" "$(echo "$CINFO" | cut -d " " -f 1)"
  echo "nice.value" "$(echo "$CINFO" | cut -d " " -f 2)"
  echo "system.value" "$(echo "$CINFO" | cut -d " " -f 3)"
  echo "idle.value" "$(echo "$CINFO" | cut -d " " -f 4)"
  if [ -n "$extinfo" ]; then
    echo "iowait.value" "$(echo "$CINFO" | cut -d " " -f 5)"
    echo "irq.value" "$(echo "$CINFO" | cut -d " " -f 6)"
    echo "softirq.value" "$(echo "$CINFO" | cut -d " " -f 7)"
  fi
}