boox-sync

#!/bin/bash
exitcode=1
mountpoints="/run/user/1000/gvfs"
#do check if the correct usb mtp device is mounted
for mountpoint in $mountpoints/mtp*/;
do
        echo "Testing $mountpoint"
        sync_folder="$mountpoint/Internal shared storage"
        #if the device contains a .sync_boox file in internal storage, proceed
        if test -e "$sync_folder/.sync_boox";then
                exitcode=0
                # files on the USB device have priority over local ones
                #from usb to folder if the files are newer
                rsync -rltvvuP --inplace "$sync_folder/" ~/boox/;
                #from folder to usb if the files are newer
                rsync -rlvvuP --inplace ~/boox/ "$sync_folder/";
                break #only check a single device
        fi
        #if the flash is not mounted exit with exitcode=1 
done
exit $exitcode