chksum check or failure invalid entry size oracle installer

When downloading an oracle patch file, it is highly important that you run a checksum test to verify the download file.
It is a common error to have a problem in the download and the zip work correctly and even a large portion of the install work before a failure occurs with an error like “invalid entry size”.

It’s easy to check the checksum of the file before working with it to be sure you have a good copy.

In linux

cksum <filename>

md5sum <filename>

or

sha1sum <filename>

Works well for an oracle file since an md5 is usually available right from the download location.