Allow inline countdown.

countdown.sh

@@ -24,27 +24,46 @@
 
 set -euo pipefail
 
-if [ $# -gt 1 ]
+INLINE=0
+COUNT=5
+
+if [ $# -ge 1 ] && [ $# -le 2 ]
 then
-	echo "Too many arguments"
+	for arg in "$@"
-	echo "Usage: $0 [COUNT]"
+	do
-	exit 1
+		if [ "$arg" = "-i" ]
-elif [ $# -eq 1 ] && [ "$1" = "-h" ]
 		then
-	echo "Usage: $0 [COUNT]"
+			INLINE=1
+		elif [ "$arg" = "-h" ] || [ "$arg" = "--help" ]
+		then
+			echo "Usage: $0 [-i] [COUNT]"
+			echo "  COUNT: Number of seconds to count down from (default: 5)"
+			echo "  -i: Inline mode (do not print each number on a new line)"
 			exit 0
-elif [ $# -eq 1 ] && [ "$1" -le 0 ]
+		elif [[ "$arg" =~ [0-9]+ ]]
 		then
-	echo "COUNT must be a positive integer"
+			COUNT="$arg"
+		else
+			echo "Unknown argument: $arg"
 			exit 1
 		fi
-
+	done
-COUNT=${1:-5}
+fi
 
 for i in $(seq "$COUNT" -1 1)
 do
+	if [ $INLINE -eq 0 ]
+	then
 		echo "$i"
+	else
+		printf "\r%s" "$i"
+	fi
 	sleep 1
 done
 
-echo 0
+if [ $INLINE -eq 0 ]
+then
+	echo "0"
+else
+	printf "\r%s\n" "0"
+fi