s/vesion/version/4:7

Hidden File Follies

A Unix user's login directory typically contains several files that begin with a dot. For example, .login, .mail, and .forward. Normally those files are hidden from view.

One day I edited my .login file using Emacs. When emacs edits a file, it saves the previous version using the same name with a ~ appended. In this case, that left me with a .login file and a .login~ file.

I didn't want to clutter my directory with the backup file because my account's space was limited so I tried to delete it. I couldn't. To the Unix file system, the character ~ means "someone's home directory." For example, ~rod might mean the home directory of the user rod. When I tried to remove the file .login~ with the following command, the operating system shell got confused.

    rm .login~

Of course them Emacs created a back of that file so now I had three files: .login, .login~, and .login~~!

Eventually I asked a sysop and, if I remember correctly, he said to try:

    rm .login\~

To Save Changes, Kill Session

I was in graduate school at MIT when the emacs editor was being written. In most Unix shops, it's common for the system administrator's to install new software without warning or testing and MIT was no exception. Whenever a new build of emacs was available, it popped onto the systems without any notice or documentation of the changes. It was common for the splash screen to show a version number like 3.276.1287. New builds were posted almost daily.

One day I logged on and spent an hour or so writing some paper or other. Then I couldn't figure out how to save my file and close emacs. They had changed the exit command and hadn't told anyone what the new command was.

After half an hour of frustration, I finally tried to kill the program and discard my changes with Ctrl-C, Ctrl-C. That was roughly the system's equivalent of Ctrl-Alt-Del, Ctrl-Alt-Del and, sure enough, that was the new command to exit the program! Not only had they changed the exit command, they had changed it to something no sane person would try. Fortunately I was practically insane with frustration at that point so I got lucky and stumbled across the magic key sequence.

Ghost Writers

MIT's computing services were set up with centralized servers linked to a network of workstations. You sat down at a workstation and connected to the server that held your account. The command window took over the entire workstation surface so you could normally run only one process at a time.

To get around that restriction, most people started programs in the background. The command

    emacs &

Unfortunately emacs had some special feature that effectively hid it from the operating system so the system didn't know you were doing anything if you only used emacs. After two hours, the system decided the terminal had been idle for too long and it disconnected you. Emacs died without saving your changes and you lost two hours' work.

To "fix" this problem, the support staff recommended that you turn on emacs' autosave feature. You would still get disconnected, but at least you would only lose five minutes' work instead of two hours'.

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