/* A system call that renames a file from given old name to given new name.
Return zero on success, non-zero otherwise. In case of failure, the file
must still be accessible by old name. Any handling of open files etc. is
/* A system call that renames a file from given old name to given new name.
Return zero on success, non-zero otherwise. In case of failure, the file
must still be accessible by old name. Any handling of open files etc. is