Sometimes extracting a zip file using the unzip command may result in the “skipping: filename.zip need PK compat. v4.5″ error message.
PHP Code:
    # unzip filename.zip
    
Archive:  filename.zip
       skipping
filename.zip  need PK compatv4.5 (can do v2.1
This is due to the file been compressed with the latest version of PKZIP which the unzip command cannot handle. The solution is to install p7zip package which can handle the files compressed using PKZIP.

Download the latest version of p7zip:

PHP Code:
    # wget http://sourceforge.net/projects/p7zip/files/p7zip/\
    
9.20.1/p7zip_9.20.1_x86_linux_bin.tar.bz2 
Extract the file

PHP Code:
    # tar -jxf p7zip_9.20.1_x86_linux_bin.tar.bz2 
goto the extracted directory and run the installer

PHP Code:
    # ./install.sh 
This will install the ’7za’ command on your server using which the zip file can be extracted
PHP Code:
    # 7za x filename.zip
     
Processing archivefilename.zip
     Extracting  filename
     Everything is Ok