Problem
How to resume a partial file downloaded from wget instead of downloading the same file from the beginning?
Solution
Use the -c/--continue option of wget
From man wget:
"Continue getting a partially-downloaded file. This is useful when you want to finish up a download started by a previous instance of Wget, or by another program."
First fetch:
# wget http://build.chromium.org/buildbot/archives/chromium.tgz
Resume partial file:
# wget -c http://build.chromium.org/buildbot/archives/chromium.tgz