With the winzip commandline addon, you can use the -n
option:
-n
Unzip only newer files. This option updates existing files if the archived file is newer and creates new ones if they do not already exist.
wzunzip -n "c:\my documents\spring2007.zip" c:\semesters\spring05
This example will extract, from c:\my documents\spring2007.zip, ONLY those files that are newer than the files that currently exist in c:\semesters\spring05 OR that do not already exist in the c:\semesters\spring05 folder.
You might want to combine it with the -o
option - "Overwrite existing files without a prompt (automatically reply "Yes" to each overwrite prompt)."