@cassidoo's interview question from July 2, 2023

reversedSquares.sh

#!/usr/bin/env bash
set -eu -o pipefail

isPerfect() {
	NUM=$1
	SQRT=$( bc -l <<< "sqrt ($NUM)" )
	INT_SQRT=$( cut -d '.' -f 1 <<< "$SQRT" )
	SQ_INT_SQRT=$( bc -l <<< "$INT_SQRT ^ 2" )
	test $NUM -eq $SQ_INT_SQRT; echo $?
}

# check input
ARGC="$#" 
if [[ "$ARGC" -ne 1 ]]; then
	echo "Please enter an integer number, e.g. 123"
	exit 1
fi
NUM="$1"
re='^[0-9]+$'
if ! [[ $NUM =~ $re ]] ; then
   echo "error: Not a number" >&2; exit 1
fi

if [ $( isPerfect $NUM ) -eq 0 ] && [ $( isPerfect $( rev <<< $NUM ) ) -eq 0 ]; then
	echo "$NUM is Perfectly Perfect!"
else
	echo "$NUM is not Perfectly Perfect."
fi

MONTASIO:cassidoo andrewrich$ ./reversedSquares.sh 9
9 is Perfectly Perfect!
MONTASIO:cassidoo andrewrich$ ./reversedSquares.sh 441
441 is Perfectly Perfect!
MONTASIO:cassidoo andrewrich$ ./reversedSquares.sh 25
25 is not Perfectly Perfect.