Clean up using shellcheck.

2017/day-02/solution.sh

@@ -3,8 +3,8 @@
 sum1=0
 sum2=0
 
-while IFS="\n" read line; do
-	sorted=$(echo $line | xargs -n 1 echo | sort -n)
+while read -r line; do
+	sorted=$(echo "$line" | xargs -n 1 echo | sort -n)
 	checksum=$(($(echo "$sorted" | tail -n 1) - $(echo "$sorted" | head -n 1)))
 
 	for a in $sorted; do
@@ -14,13 +14,13 @@ while IFS="\n" read line; do
 			fi
 
 			if [[ $((a % b)) -eq 0 ]]; then
-				sum2=$((sum2 + a / b))
+				((sum2 += a / b))
 				break
 			fi
 		done
 	done
 
-	sum1=$((sum1 + checksum))
+	((sum1 += checksum))
 done
 
 echo Sum 1: $sum1