Renice a process and all of its children recursively, passing both the nice value and the pid

my_renice.sh

#!/usr/bin/env bash

# This can be run simply by passing it the outputs from pgrep:
#  my_renice 10 $(pgrep application)
#
# You may also want to use pgrep to find more complex processes based on arguments
#  my_renice 10 $(pgrep -f "bash.*$name")

function my_renice(){
  newnice=$1
  pid=$2

  # Return if pid not found
  if [ -z $pid ]; then return; fi

  # Renice pid right away in case we spawn more children
  renice $newnice $pid

  # Find children pids
  children=$(pgrep -d ' ' -P $pid)

  # Loop through children
  for i in $children; do my_renice $newnice $i; done
}