Computers in Research: Learning How to Log into Hardin

I. To run the SPSS program for statistical analysis, our class will rely on Northwestern’s “hardin” and “seldon” computers, which run the “unix” operating system in a “distributed computing environment.” A. Hardin is an Hewlett-Packard J210 computer, with two CPUs. Seldon is an HP 735 with less computing capacity that serves files to hardin and other some computers. They are named after characters in a futuristic novel by I. Asimov.   B. Like DOS, Windows, or the Macintosh OS, unix is a command system for controlling a computer. It was originally created in 1969 by researchers at Bell Laboratories, so it is not new. Nevertheless, it has been intensely championed by people in the hard sciences and in computer sciences as “the” operating system. Its many admirers notwithstanding, unix commands are viewed by outsiders (e.g., me) as cryptic and confusing. Nevertheless, it is what we have to work with so you will have to learn enough unix to serve you well in this course. I will try to teach unix by example of usage; use the class handout on unix for reference and review. C. The meaning of a "distributed computing environment" (DCE). In principle, DCE refers to the ability to store and process files on multiple computers that are networked together. Most files are stored on seldon, but that fact will be transparent to you. Your account will be on the hardin computer, to which you will log in. II. How to log into hardin (remember, unix is case-sensitive and usually uses lower case for its commands) As explained in the syllabus, this can be done via microcomputers connected to the campus network or via telephone lines. III. Follow this example for logging into hardin after you receive the unix prompt, “login”. In this example:   plain type is hardin talking; boldface is my reply     login:kjanda <---Enter your account identification, then press RETURN or ENTER, depending on your keyboard   Please wait.checking for disk quotas Password:[my password, RETURN] <---response on entering hardin. <--Various messages are listed here.   No mail. <---an e-mail program comes with hardin, but DO NOT use it for e-mail; you’ll be punished.   Scratch dir is /scr01/kjanda. <--Tells the name of your “directory” on a “scratch disk” for temporary storage   ********************************************* C 1 0 - S T A T I S T I C S - B U L L E T I N ********************************************* CONGRATULATIONS!! You successfully logged into hardin and activated the C10 Statistics "setup" routine. From now on, you will see a "bulletin" each time that you log into your account. In the future, I will use this space for messages about your statistics assignments. No message for now. KJ   hardin(kjanda) 41%logout <---You return to the unix prompt at this point. Type logout to exit the computer. Some essentials about the unix operating system and your account on hardin (adapted from Bruce Foster’s material):   Just as with any computer system, you will quickly generate multiple files stored on your hardin account. File names on unix are sensitive to upper and lower case, e.g, Myfile and myfile are different. Unlike DOS and even Macintosh, unix file names can be up to 255 characters long. File names can contain any character except a slash, /. Some file types are recognized by their extensions, e.g., SPSS “system” files are tagged with a .sav extension--i.e., states.sav.   Under unix, similar to DOS, files can be organized in a hierarchical fashion under directories, which are separated by slashes. Each of you have a “home directory,” which is your working directory when you log in. At the unix prompt, you can tell what directory you are in by typing pwd for "print working directory."   Because directories can be confusing under unix, I will suggest that you not try to create different directories but that you store all your files in your default working directory.There are different ways to list the files stored in your working directory, according to these commands: ls lists the contents of your working directory in ascending order, organized into vertical colums to fill the width of the screen. ls -l lists its contents with additional information: showing the file mode, number of links, owner, size in bytes, and time of modification--more knowledge than you probably want.     Changing the name and copying files: Unix has no “rename” command but mv (move) will rename a file: mv [oldname] [newname] Files can be copied as follows: cp [filename1] [filename2] Files can be removed as follows: rm [filename] The main way to view text files at a unix prompt is with a program called “more”: type more [filename] to display the file. Some major commands you will need: pressing the space bar moves the screen forward type b to page backward G goes to the end of a file g goes to the beginning h displays a brief help display and command summary typing q terminates the listing How to print a file:   lp -dcresap115 [filename] lpstat cresap115 cancel [ID] sends the file to the printer in Cresap Lab, room 115 displays the IDs of print requests, if they are queued up will cancel the printing of a job, if it hasn’t printed yet.   How to log out of hardin: use logout or exit Other suspects--log, logoff, quit--will not work.