Downloading a File in an Unreliable/Flaky Connection

Many of us find ourselves stuck in a place where we have a very unreliable/flaky connection and need to download a file urgently. Most likely you don't have an external download manager (those were popular in age of IE 6), and using a browser to download restarts the download from beginning every time. With a lot of luck you hope the download is successful this time. I went through the same when I spent my New Year holidays with family in a not so connected to internet part of India.

Obviously, one such solution that props to mind is using curl with "-C" continue the download flag. So using curl your command is going to look like

curl -L -O http://xyz.url

and when the download has failed, switch over to command

curl -L -O -C - http://xyz.url

But this have another problem. You have to constantly monitor the download and launch the command as soon as it craps. Curl helps you by returning an error exit value if the download was not successful and otherwise. Wish there was a command to relaunch it based on the exit flag. Since there is none, ruby can come to your rescue. We can write a small ruby script to do just that. The ruby script looks like

ruby -e "while(\!system(\"curl -L -O -C - http://xyz.url\")); end"

Hope this helps. Happy New Year !