echo "not enough Space" >&2

https://stackoverflow.com/questions/23489934/echo-2-some-text-what-does-it-mean-in-shell-scripting

To quickly explain what the others missed:

echo "hey" >&2

> redirect standard output (implicit 1>)

& what comes next is a file descriptor, not a file (only for right hand side of >)

2 stderr file descriptor number

Redirect stdout from echo command to stderr. (If you were to useecho "hey" >2 you would output hey to a file called 2)

https://stackoverflow.com/questions/41127585/shell-how-to-check-available-space-and-exit-if-not-enough

#!/bin/bash

# Note: Numbers are 1024-byte units on Linux,

#       and 512-byte units on macOS.

reqSpace=100000000

availSpace=$(df "$HOME" | awk 'NR==2 { print $4 }')

if (( availSpace < reqSpace )); then

  echo "not enough Space" >&2

  exit 1

fi