I have files
server.log
.server.log.swo
.server.log.swp
how to open swo and swp?
Those are temporary files created by the vim editor. The .swp is created when a file is opened in the editor. The .swo is created if the file is edited and the .swp already exists. Edit it a third time and you get a .swn, and so on. When vim is closed, those files should go away. If vim crashes or is killed, they may be left behind. They are safe to ignore.