def delete(pattern)
  files = Dir[pattern]
  rm(files, verbose: true) unless files.empty?
end

desc "Remove files whose names end with a tilde"
task :delete_unix_backups do
  delete("*~")
end

desc "Remove files with a .bak extension"
task :delete_windows_backups do
  delete("*.bak")
end

desc "Remove Unix and Windows backup files"
task delete_backups: [:delete_unix_backups, :delete_windows_backups] do
  puts "All backups deleted"
end
