showiotop

#!/bin/bash

# Extract the top process of iotop.
# Optional ~/.showiotop/showiotop_col.txt to change default column 9, since there are various versions of iotop out there. 0 Means do nothing (e.g., if iotop is not granted sudo, see below).
# Obviously needs iotop, and add (with your <user>)
# ## Allow root to run any commands anywhere”)
# <user> ALL=(ALL) NOPASSWD:/usr/bin/iotop
# to /etc/sudoers

colno=9

if [[ -f ~/.showiotop/showiotop_col.txt ]]
then
 colraw=`cat ~/.showiotop/showiotop_col.txt`
 re='^[0-9]+$'
 if ! [[ $colraw =~ $re ]]
 then
  echo "~/.showiotop/showiotop_col.txt needs to be a nonnegative integer" >&2; exit 1
 elif [[ $colraw == "0" ]]
 then
  exit 0
 else
  colno=$colraw
 fi
fi

sudo iotop -obn 1|
awk -v coln="$colno" '$1 ~ /^[0-9]+$/ {print($coln)}'|
head -n 1