Creating The Install File – Zip
Zip your file or files following the instructions here.
The files executable permission is kept when it is zipped and will remain when it is unzipped again.
Copy the .gz zip file to the public folder in your dropbox.
Get its public link.
Instructions To Then Install From The Dropbox Zip
If upgrading, on the Raspberry Pi ensure the application isn't already running.
Press the bottom left start button, select 'Accessories' and then 'LXTerminal'
This opens the Linux command prompt. Enter this command:
Now enter this command to download the new version
wget -N https://dl.dropboxusercontent.com/u/123456789/your_zip_file.gz
Wait for it to complete (it will probably take a few seconds). Then enter this to install it:
tar zxvf your_zip_file.gz
That's is, assuming you didn't get any error messages the new version is installed
The "-N" option causes the wget to overwrite the local file if it already exists (otherwise you_zip_file.gz.1 is created instead) and to only bother with the download if the remote file is newer. If you ommit it then if a file with the same name already exists it will be retained and the new file renamed with ".1" on the end.
Simpler Instructions For Downloading The Executable Directly
sudo killall my_app_name
sudo wget -N http://www.my_website.com/apps/my_app_name
sudo chmod +x /home/pi/my_app_name
This does the following:
Stops the application if it is already running
Downloads the new version, overwriting the existing file if present.
Sets it to executible