diff --git a/clone/clone b/clone/clone
index b1db5a3..18addd6 100755
--- a/clone/clone
+++ b/clone/clone
@@ -17,20 +17,28 @@ echo "<<< done";
 # [!] Check parameter : device file
 #========================================================#
 echo ">>> [!] Checking parameter : device";
+
 # (1) Check parameter existence #
-test $# -lt 1 && echo "Missing parameter : device" && exit;
+if [ $# -lt 1 ]; then
+	echo "Missing parameter : device"; exit 1;
+fi
 
 # (2) Check USB and not a hard drive !!!!!!!!!! #
 device_type=$(udevadm info --query=all -n $1 | grep -E "ID_BUS" | awk '{print $2}' | sed 's/ID_BUS=//');
 
-test $device_type != "usb" && echo ">>> ERROR: device type is $device_type, \"usb\" expected." && exit;
+if [ "$device_type" != "usb" ]; then
+	echo ">>> ERROR: device type is $device_type, \"usb\" expected."; exit 1;
+fi;
 
 echo "<<< done";
 
 
 echo ">>> [!] Checking debian image";
 # (1) Check parameter existence #
-test ! -e $IMAGE_FILE && echo -e "debian image '$IMAGE_FILE' not found" && exit;
+if [ ! -e $IMAGE_FILE ]; then
+	echo -e "debian image '$IMAGE_FILE' not found";
+	exit 1;
+fi;
 
 echo "<<< done";
 
@@ -57,7 +65,12 @@ step1(){
 
 		read -p "    (!) umount $mounted (y/n) [n]" unmount;
 
-		test -n "$unmount" && test $unmount = "y" && sudo umount $mounted 2> /dev/null > /dev/null && echo "    > unmounted";
+		if [ -n "$unmount" ] && [ $unmount = "y" ]; then
+			sudo umount $mounted 2> /dev/null > /dev/null \
+				&& echo "    > unmounted" \
+				|| echo "    > error";
+		fi;
+
 	done;
 	echo "<<< done";
 
@@ -76,8 +89,15 @@ step2(){
 
 	# (1) Confirmation #
 	read -p"    (!) Erase the whole disk ? it is irreversible! (y/n) [n]" confirm_format;
-	test -z "$confirm_format"   && echo "<<< aborting" && exit;
-	test $confirm_format != "y" && echo "<<< aborting" && exit;
+	if [ -z "$confirm_format"   ]; then
+		echo "<<< aborting";
+		exit 1;
+	fi;
+
+	if [ $confirm_format != "y" ]; then
+		echo "<<< aborting";
+		exit 1;
+	fi;
 
 	# (2) Init gpt entry #
 	echo -e "g\nw" | sudo fdisk $DEV 2> /dev/null > /dev/null;
@@ -100,8 +120,15 @@ step3(){
 
 	# (1) Confirmation #
 	read -p"    (!) Burn the whole disk ? it is irreversible! (y/n) [n]" confirm_burn;
-	test -z "$confirm_burn"   && echo "<<< aborting" && exit;
-	test $confirm_burn != "y" && echo "<<< aborting" && exit;
+	if [ -z "$confirm_burn" ]; then
+		echo "<<< aborting";
+		exit 1;
+	fi;
+
+	if [ $confirm_burn != "y" ]; then
+		echo "<<< aborting";
+		exit 1;
+	fi;
 
 	# (2) Burning image into disk #
 	# if GZIP
@@ -145,7 +172,10 @@ step4(){
 		sleep 1;
 	done;
 
-	test $count -eq 5 && (echo "<<< error: can't find device ${DEV}2"; exit 1);
+	if [ $count -eq 5 ]; then
+		echo "<<< error: can't find device ${DEV}2";
+		exit 1;
+	fi;
 
 	# [1] Mount device partition
 	sudo mount ${DEV}2 /mnt || (echo "<<< error: can't mount"; exit 1);