If you prefer, you can say cd instead of chdir . Files and directories have permissions. Unless you explicitly set permissions, all your files can be read by anybody on the machine. It is a violation of the Policy Governing Access to and use of University of Kentucky Computing Resources to look at someone else's files, even if file permissions allow, without the owner's consent. If your program is not responding, some keyboard escapes can tell it to quit.
Programs can ignore such requests, though.
You can see each item by typing its number. You can delete the current item with the d command. To exit and save those messages you have not deleted, type q . To exit without making any changes to your incoming mail, type x . You can also respond to mail with the r command.