diff --git a/dotinstall.sh b/dotinstall.sh
index 552a397..a689f34 100755
--- a/dotinstall.sh
+++ b/dotinstall.sh
@@ -1,18 +1,94 @@
 #!/bin/sh
 
-cd $(dirname $(echo $0))/src/
+# Symlink dotfiles into the home directory
+
+set -e
+
+SCRIPT_NAME="$(basename $0)"
+
+# Default source for dotfiles
+SRCFOLDER="$(dirname "$0")/src/"
+DESTFOLDER="$HOME"
+
+# Allow overwriting of outdated files
+FORCE="N"
+VERBOSE="N"
+
+display_help () {
+cat >&2 <<EOF 
+usage: $SCRIPT_NAME [-h] [-v] [-f] [-s PATH] [-d PATH]
+	-h: display help
+	-f: allow overwriting existing dotfiles
+	-v: print modified files
+	-s: path to source of dotfiles
+	-d: path to destination where dotfiles are linked from
+EOF
+}
+
+while getopts "fvhs:d:" o; do
+	case "$o" in
+		h) 
+			display_help
+			exit 0
+			;;
+		f) FORCE="Y" ;;
+		v) VERBOSE="Y" ;;
+		s)
+			DESTFOLDER="$OPTARG"
+			;;
+		d)
+			DESTFOLDER="$OPTARG"
+			;;
+	esac
+done
+
+if ! [ -d "$SRCFOLDER" ]; then
+	printf "$SCRIPT_NAME: source folder $SRCFOLDER is invalid.\n"
+	exit 1
+fi
+
+if ! [ -d "$DESTFOLDER" ]; then
+	printf "$SCRIPT_NAME: destination $DESTFOLDER is invalid.\n"
+	exit 1
+fi
+
+cd $SRCFOLDER
 
-echo Making directories
 for f in $(find -type d); do
-	DIR=$HOME$(echo $f | cut -c 2-)
-	echo $DIR
-	mkdir $DIR
+	DIR=$DESTFOLDER$(echo $f | cut -c 2-)
+	
+	if ! [ -d "$DIR" ]; then
+		if [ "$VERBOSE" = "Y" ]; then
+			printf "$DIR\n"
+		fi
+		mkdir $DIR
+	fi
 done
 
-echo Symlinking dotfiles
+link () {
+	SRC="$1"
+	DEST="$2"
+	OPTS="$3"
+
+	ln -s $OPTS "$SRC" "$DEST"
+
+	if [ "$VERBOSE" = "Y" ]; then
+		printf "$2\n"
+	fi
+}
+
 for f in $(find -type f); do
-	DEST=$HOME$(echo $f | cut -c 2-)
-	SRC=$PWD$(echo $f | cut -c 2-)
-	echo $SRC $DEST
-	ln -s $SRC $DEST
+	DEST="$DESTFOLDER$(echo $f | cut -c 2-)"
+	SRC="$PWD$(echo $f | cut -c 2-)"
+	if [ -e "$DEST" ]; then
+		if ! [ "$SRC" -ef "$DEST" ]; then
+			if [ "$FORCE" = "Y" ]; then
+				link "$SRC" "$DEST" -f
+			else
+				printf "$SCRIPT_NAME: $DEST already exists\n" >&2
+			fi
+		fi
+	else
+		link "$SRC" "$DEST"
+	fi
 done
diff --git a/src/.local/bin/msync b/src/.local/bin/msync
index dcd6ff5..19c3e42 100755
--- a/src/.local/bin/msync
+++ b/src/.local/bin/msync
@@ -4,14 +4,35 @@
 
 set -e
 
-while getopts ":pr" o; do
+SCRIPT_NAME="$(basename $0)"
+
+ACTION=NONE
+
+MNT="$HOME/quar/mnt"
+DEST="$HOME/quar"
+
+while getopts "prhs:d:" o; do
 	case "${o}" in
 		p) ACTION=PUSH ;;
 		r) ACTION=RECV ;;
+		h) ACTION=HELP ;;
+		s)
+			ROOT="$OPTARG"
+			if ! [ -e "$MNT" ]; then
+				printf "$SCRIPT_NAME: source mountpoint $MNT does not exist"
+				exit 1
+			fi
+			;;
+		d)
+			DEST="$OPTARG"
+			if ! [ -e "$DEST" ]; then
+				printf "$SCRIPT_NAME: destination $DEST does not exist"
+				exit 1
+			fi
+			;;
 	esac
 done
 
-MNT="$HOME/quar/mnt"
 ROOT="$MNT/Internal shared storage"
 
 imp () {
@@ -26,33 +47,53 @@ exp () {
 	find "$1" -type f | xargs -I{} cp -n "{}" "$2"
 }
 
-if [ $ACTION = PUSH ]
-then
-	# Optionally send sorted files back
+display_help () {
+	cat << "EOF"
+usage: $SCRIPT_NAME [-r] [-p] [-h] [-s PATH] [-d PATH]
+	-r: receive files from mobile device
+	-p: send files to mobile device
+	-s: set go-mtpfs source mountpoint path
+	-d: set local download destination path
+EOF
+}
 
-	exp ~/med/memes/woof/ "$ROOT/Pictures/memes/"
-	exp ~/med/memes/bork/ "$ROOT/Pictures/memes2/"
-	exp ~/med/rw/sch/ "$ROOT/Pictures/rw/sch/"
-	exp ~/med/sticker/ "$ROOT/Pictures/sticker/"
-fi
+case "$ACTION" in
+	PUSH)
+		# Optionally send sorted files back
 
-if [ $ACTION = RECV ]
-then
-	# Move files to the quarantine zone for categorisation and renaming
+		exp ~/med/memes/woof/ "$ROOT/Pictures/memes/"
+		exp ~/med/memes/bork/ "$ROOT/Pictures/memes2/"
+		exp ~/med/rw/sch/ "$ROOT/Pictures/rw/sch/"
+		exp ~/med/sticker/ "$ROOT/Pictures/sticker/"
+		;;
+	
+	RECV)
+		# Move files to the quarantine zone for categorisation and renaming
 
-	imp "$ROOT/Pictures/Infinity/" ~/quar
-	imp "$ROOT/Pictures/Screenshots/" ~/quar
+		imp "$ROOT/Pictures/Infinity/" $DEST
+		imp "$ROOT/Pictures/Screenshots/" $DEST
 
-	imp "$ROOT/Movies/Infinity/" ~/quar
+		imp "$ROOT/Movies/Infinity/" $DEST
 
-	imp "$ROOT/DCIM/OpenCamera/" ~/quar
-	imp "$ROOT/DCIM/Camera/" ~/quar
+		imp "$ROOT/DCIM/OpenCamera/" $DEST
+		imp "$ROOT/DCIM/Camera/" $DEST
 
-	imp "$ROOT/Recordings/Sound records/" ~/quar
+		imp "$ROOT/Recordings/Sound records/" $DEST
 
-	imp "$ROOT/Documents/dr" ~/quar
+		imp "$ROOT/Documents/dr" $DEST
 
-	imp "$ROOT/Documents/contacts.vcf" ~/quar
-	imp "$ROOT/infbk/" ~/quar/infinity/
-	impf "$ROOT/.SeedVaultAndroidBackup/" ~/quar/seedvault/
-fi
+		imp "$ROOT/Documents/contacts.vcf" $DEST
+		imp "$ROOT/infbk/" $DEST
+		impf "$ROOT/.SeedVaultAndroidBackup/" $DEST/seedvault/
+		;;
+
+	HELP)
+		# show help
+		display_help
+		;;
+	
+	NONE)
+		# Default
+		printf "$SCRIPT_NAME: no option specified, see $SCRIPT_NAME -h for help"
+		;;
+esac