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.
the files remain even after vim is closed we need to use vim in recover mode, save and then move the files to a different name. then delete the .sw* files.