Recently, I encountered a requirement to extract the wsps from SharePoint Content Database and extract its contents. Extraction of WSP is already mentioned in many blogs. So, I would just guide how to extract the WSP contents.
Following is the command which is used to extract the WSP contents and saves its contents to a particular path:
expand <FullPathToWSP> <DirectoryWhereFileNeedsTobeExtracted> -F:*
The above command is a built-in Windows utility which extracts the content of WSP. Following is the example of the above mentioned command.
expand C:\mySolution.wsp C:\SolutionExtract\mySolution -F:*