I have a project that depends upon some other binaries to be downloaded from web at install time.For this what i do is:

if ( file-present-in-src/)
    # skip that file
else
    # use wget to download the file

The problem with this approach is that when I interrupt a download in middle, and do invoke the script next time, the partially downloaded file is also skipped (which is not desired), also I want wget to resume the download of the partially downloaded file.

How should I go about it: Possible Solutions I could think of:

1. Let the file to be downloaded to some file say download_tmp. Copy to original file if successful.
2. Handle SIG{'INT'} to write proper cleanup code.

But none of these could help resume the partial file download,

Any insights?