Given a file, say, XXXX.tar.gz, developers often need to make sure it's integrity is correct. Generally we do this obtaining a sha1sum of it.
** In Linux: use sha1sum in linux on the tar/zip file, e.g. <code>sha1sum XXXX.tar.gz</code>** In Windows: use a tool like the [http://www.shareup.com/HashCalc-download-22889.html HashCalc utility]** In Mac OS X, use [http://beeblebrox.org/hashtabmac/ Hashtab]