add unscan and dispatch command

scanbuddy.bash

@@ -21,6 +21,7 @@ resolution='300'
 current_page=$(find "$PWD" -name "out*.pdf" | sort | tail -n 1);
 read -r current_pageno <<<"${current_page//[^0-9]/ }"
 current_pageno=${current_pageno:-0}
+last_out_file="out$current_pageno.pdf"
 next_out_file="out$((current_pageno+1)).pdf"
 
 scan() {
@@ -74,13 +75,17 @@ scan() {
     --resolution="$resolution" \
     --source="$sides" \
     -x 210 -y 297 # A4 
-
 }
 
 case "$1" in
   scan)
     scan "${@:2}"
     ;;
+  unscan)
+    rm "$current_pageno"
+    ;;
+  dispatch)
+    ;;
   *)
     echo "Usage: scanbuddy"
     ;;