• begin : file
• current : file
• current_user_and_admins_only : file
• current_user_only : file
• empty : file
• end : file
• existing : file
• flag_keepalive : socket
• flag_nodelay : socket
• invalid : result , rwresult
• nodir : result
• nofile : result
• noperm : result
• nospace : result , rwresult
• other : result , rwresult
• wouldblock : rwresult