Use this in your bash backup function or with cron to sync a local file/directory with your phone without having to go through a cloud service

1. install adb
2. connect your Android phone to your laptop via USB
3. run wireless_adb_file_push.sh
4. the script connects wirelessly to your phone, saves the phone's IP address in ip.txt for future use and copies the file/directory you enter into the Downloads folder in your phone
5. if you want to push a new file, you can run the script without connecting via USB as long as ip.txt is in the same directory. If your IP address changes, rm ip.txt, connect with USB and run the script again