If you follow the Apple news/rumor sites, you’ll have heard that Apple has been (pre-)releasing software like crazy lately. I can neither confirm nor deny these rumors. Between my marginal ISP and the dank, dusty cellars underneath Apple’s public website, I get plenty of half-finished large downloads regardless of what Apple is up to.
When Safari thinks it’s finished downloading an incomplete file, I like to use curl to finish. My usual trick isn’t enough for the Apple Developer Connection’s password-protected files, and it took me a while to figure those out. Eventually, with the help of two helpful posts and some trial-and-error, this is the method I’ve settled on:
- Copy partially downloaded file if it’s fairly large (because sometimes I mess up)
- Log into ADC in a browser, and copy the download link
curl -c $(mktemp -t curl) -L -o '<Partially Downloaded File>' -C - '<Download URL>'
It is very important to quote the Download URL, because it may contain special shell characters! This is the main reason I copy the partial download; I don’t want to blow away a large partial download with a bit of error page HTML.
This works as follows:
-c $(mktemp -t curl) tells curl to keep track of cookies in a temporary file, and
-L means to follow redirects. The downloaded output file is specified via
-C - means to continue at the offset where this output file stops. I don’t include an option to automatically retry on failure, because if the session expires this could lead to a loss of the newly appended data if the download is replaced by an error page.