bin/mnt: Add new utility

1 files changed, 105 insertions, 0 deletions

diff --git a/bin/mnt b/bin/mnt
new file mode 100755
index 0000000..a666e48
--- /dev/null
+++ b/bin/mnt
@@ -0,0 +1,105 @@
+#!/bin/sh
+set -eu
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  mnt [-U UUID] ACTION NAME
+		  mnt -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+
+		Options:
+		  -U UUID       the id of the device under /dev/disks/by-uuid/
+		  -h, --help    show this message
+
+		  ACTION        either "on" or "off"
+		  NAME          the name of the external device
+
+
+		Automate mounting and unmounting encrypted files.
+
+
+		Examples:
+
+		  Mount UTCLOUD:
+
+		    $ mnt up UTCLOUD
+	EOF
+}
+
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+while getopts 'U:h' flag; do
+	case "$flag" in
+		U)
+			UUID="$OPTARG"
+			;;
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+ACTION="${1:-}"
+NAME="${2:-}"
+
+eval "$(assert-arg -- "$ACTION" 'ACTION')"
+eval "$(assert-arg -- "$NAME"   'NAME')"
+
+if [ -z "${UUID:-}" ]; then
+	F="${XDG_DATA_HOME:-$HOME/.local/share}/mnt/id-mappings/$NAME"
+	if [ ! -e "$F" ]; then
+		printf 'Missing -U UUID, or entry in "%s".\n' "$F"
+		usage >&2
+		exit 2
+	fi
+	UUID="$(cat "$F")"
+fi
+
+
+up() {
+	pass show disks/"$NAME" |
+		head -n1 |
+		tr -d '\n' |
+		udisksctl unlock -b /dev/disk/by-uuid/"$UUID" --key-file=/dev/stdin
+	udisksctl mount   -b /dev/mapper/luks-"$UUID"
+}
+
+down() {
+	udisksctl unmount -b /dev/mapper/luks-"$UUID"
+	udisksctl lock -b /dev/disk/by-uuid/"$UUID"
+}
+
+case "$ACTION" in
+	up|down)
+		"$ACTION"
+		;;
+	*)
+		printf 'Unsupported ACTION: "%s".\n' "$ACTION"
+esac