While intended as a general introduction for Unix use, this was written with Sun machines in mind. Some statements may be Sun specific. Please note that there are slight differences between UNIX standards of various manufactureers (SUN, SGI, IBM, DEC,...).
Contents:
We assume that you have been given an account on the Physics
Department Suns, and have been told your username (perhaps
jsmith ) and a preliminary password (say 123).
The first thing you must know is how to log into and log off of the
computer. Be sure you always log off when you stop using the computer,
for otherwise anyone can sit at the machine and tamper with your
work or e-mail eventually causing ireparable damage. You will be held
responsible for anything done by someone logged in as you.
In general, when you want to do computing, you can
find a computer which is not in use.
These can be found in Serin public computing rooms 103, 341, 383
and in ARC room 230 or in the offices where you might have permission
to use particular machine.
If connecting remotely machine name everyone should
login into for their general computing needs on the Suns
is
physics.rutgers.edu
The machine may be
displaying the screensaver, or it may be blank. Moving the mouse or hitting
a keyboard key will give one of the following:
Please type in your username.
Capital and
lower case letters are different. Hit <ret> at
the end of your username.Same kind of screen appears after entering username,
in order to take your password. In response to the password prompt, type in your password. It will not
appear as you type it, to protect its secrecy.
Hit <ret> to enter it.
Some other options available at this point will be discussed below.
This should get you logged onto the computer.
There are some options in the log-in window for Sun machines. Pressing the OK button or enter key
would submit your username/password. Start Over button is usefull to start
over when your attempt for logging in has failed and hung-up (for example
due to a network failure). The Help button is there for help instructions.
Options gives you several menu choices. Language is
set to English by default, but you are welcome to try other languages for
a system communication if you please. The Session menu offers CDE (Common Desktop Environment), Gnome,
Last Desktop and Fail Safe options. CDE and Gnome are two similar
yet different Graphic User Interfaces (GUI) which X windows can use. Within each of
them you can customize settings (say background or applications open by default)
and save them. The Last Desktop option makes use of this: if you chose it, it will
open your desktop environment as you have left it when you logged out
last time. Fail Safe session opens just plain (non-X) terminal window. It is useful when
one has problems with the system and wants to avoid eventual problems when X windows open.
The first thing you should do with your new account is to make sure
that your password is known and knowable only by you. If you have been
assigned a password by the administrator, you must change it right
away. First decide on a new password. It should have at least 8
characters, should contain at least three of 1) lower case letters,
2) Upper case letters, 3) numbers, 4) punctuation and 5) other characters.
It must not be a word found in the dictionary. (ANY dictionary! If you choose a
word in Romanian, there is a good chance the hacker trying to guess
your password expects it to be in Romanian and has a Romanian
dictionary.) In fact, there are all sorts of other restrictions too, so
you may need to try several choices before one works. Take this step
seriously.
Computers have gotten far more complex than you imagine, and our
machines are subject to break-ins from anywhere in the world. The most
common way for hackers to break in is to guess a user's password.
Hackers may often do no damage but could do very severe damage,
including getting us permenently banned off the Internet for abuses, so
don't be negligent about your password.
Also, don't share your password with others. Anyone with a legitimate
reason to get on our computers can get an account, and doesn't need to
use yours. If you need to share files, this can be arranged without
sharing passwords.
You will be held
responsible for anything done by someone logged in as you.
In the examples shown below, what you type is in
typewriter bold if
you are to type it literally, or italics if it represents
something you choose and type. Every line of a command needs to be
followed by a <ret> .
What the machine types is in
typewriter font.
To change your password, enter the command
If you did it correctly, your password will be changed as indicated by
the message
Changing password on one physsun[n] machine, changes it on all of
them in the cluster. You do not have separate password for each physsun[n].
Don't forget your password, but don't write it down where anyone
can see it either!
To log-off,
in CDE X window
environment you just press EXIT button at the toolbar.
Answer any prompt displayed by the computer by left-clicking on appropriate buttons.
Wait and check that the log-in
window appears, indicating that you have successfully logged-out.
Similarly in Gnome X windows click on Gnome meny link on the toolbar and pick "logout" icon.
If you cannot log off the computer, get help. Send mail to
help@physics.rutgers.edu.
Both for security purposes and to avoid causing your dead or run-away
processes to eat-up computing resources and initiate computer hang-ups:
After succesful log-in you will start (typically) a X window session
in either CDE or Gnome. Use of these two GUIs is similar, but appearance
and customization are different.
Essential functions
in CDE environment might be accessed from the toolbar with quite
obvious icons at the bottom of the screen and by right-clicking
on the empty portion of the screen and using the menu that will appear.
Gnome is a second choice on Solaris9 computers instead of Solaris7/8 OpenWindows.
Gnome is well-known among Linux users. By default in either GUI
some kind of help-manager will pop-up during your first session.
You can keep it open and learn or close it and recall it when needed from the menu.
To start terminal window in CDE, use right-click menu, choose
PROGRAMS and in the following menu opt for TERMINAL or CONSOLE
at your convinience. 4 panels on the CDE toolbar labeled One, Two,
Three and Four are buttons which can switch you between 4 different
desktop areas, all of which you can use at will. In Gnome you may
launch a terminal window by right-clicking for a menu, choosing Utilities and
within them Console.
In both environments minimized applications remain
displayed on a screen as icons. Applications can be accessed either by
chosing them from menus, clicking on their icons or by running them from the terminal window.
Note that if you enter command mozilla (or any other application)
in a terminal window, terminal window will be locked-up by that application. Using
mozilla & will allow you use of that terminal window even
after application have begun. Eventual error messages from the application will
still appear in that terminal window.
In both environments menus allowe you customization of appearance, start-up session,
defaults, etc.
For more detailed overview of CDE and
Gnome 2.0 documentation.
For more information about using X windows at Rutgers University please see
RUCS maintained
page on this subject.
Computer keyboards are somewhat more complicated than an ordinary
typewriter,
but you will not use all of the keys. We will discuss just a few
things
you will need to know.
You will be using the keyboard to enter commands to the computer
operating system (or shell, and
for preparing files or documents using an editor.
Typing in commands to the ``shell'', or typing in text to an editor such as
``emacs'' or ``vi'', is done just by hitting the keys, as for an ordinary
typewritter. However, you can correct mistaken keystrokes by hitting
the <del> or delete key,
repeatedly if necessary. Capital letters are
entered, as on a typewriter, by holding down the shift key and hitting
the letter key, then releasing the shift key. There is a second form
of shift, called control. The control key works in the same way as
the shift key (that is, you hold it down while hitting a character
key), but it enters a different character, usually invisible. The use
of such characters depends on whether you are ``talking to the
shell'',
In emacs editor ,
many of the control keys execute editting commands. For
example, to exit from emacs you type
ctrl-x ctrl-c. Emacs also uses the ``escape'' key
<esc>. Escape is not a shift key, but an ordinary (though
unprintable) character. So an emacs command involving escape, such as
<esc> v, is entered by first hitting and releasing the escape
key, and then doing the same for the v key.
Emacs also uses the arrow keys to move the cursor,
which indicates the point of the text
at which new characters will be inserted. These keys are usually found
to the right of the normal keys, possibly on the 8, 2, 4, 6 keys of
the ``numerical keypad''.
Most keyboards have an unfortunate ``Caps lock'' key, which enters a mode in
which it is
impossible to enter lower case characters. Some light will come on
somewhere
on the keyboard when in this mode. Hit the caps lock key again to
clear it. You almost never want to be in this mode.
Many of the other keys on the keyboard also have unfortunate
consequences, so try to avoid hitting them until you know what they
do.
Everything stored permanently on the computer
(
Files which can be read directly are known as ``ascii'' files.
Such files can be examined with the command more, say
Files may be created by a human using an editor, such as emacs, or
they may be the output of some program.
The editor we support and most people use is named ``emacs'', or more correctly
``gnuemacs''. It is a very complex editor with capabilities that will
satisfy the most sophisticated computer user, and unfortunately this
means that it is not the easiest editor to learn. However, you can
effectively edit after learning only a few of the commands. Paralel to emacs,
some developers developed so called Xemacs. Commands and default
start-up file (.emacs) are shared between these. Xemacs just has more GUI
capabilities (as far as begining user is concerned).
There is a
tutorial which you can run to learn how to use emacs.
It is run by the command
When you want more sophisticated information, you will find in
/physics/doc/physics/emacs and some in
/physics/doc/supplementary. There are
also printed manuals and
information about emacs on the Internet .
But emacs is hugely complicated and no physicist
should decide to set out to learn it completely, so take an
evolutionary approach.
Files of certain kinds can be printed. You should only print things
for which you have a good reason to want a paper copy --- look at the
files on the screen first, and only print them after checking they are
what you want, are correct, and asking yourself if you really need a
paper copy. Remember that you can always look at the file in another
window.
Printing is more expensive and more time-consuming than xeroxing. Please
make only one copy and xerox it if you need multiple copies.
Readable ascii files can be printed with the command
The printing can be done at any one of several locations, as indicated
by the printer names:
The default printer if you print from computers in the ARC building
is arc;
on other computers the default printer will be something else.
If you want to set a particular printer as your default regardless of which
computer you print from, enter a line as follows in your .cshrc file in your
home directory:
setenv PRINTER printername
If you want to print a single job on a
printer other than your default printer, you can use the -P
flag for lpr . For example,
Other kinds of files are also printable. A properly constructed
PostScript file, beginning with the two characters %! , will print
satisfactorily with the lpr command.
A .dvi file, say paper.dvi
as produced by
TeX or LaTeX, can be printed with the command
If you experience problems in printing, see
Problems Printing PostScript Files.
If you want to reformat postscript files, see
Hints for reformatting Printing PostScript Files. Also, report any
printing problems to
printmaster@physics.rutgers.edu .
The Suns in the Physics Department support programming in Fortran and
C/C++, and also in the symbolic mathematics languages Mathematica and Maple.
It used to be that all physicists used Fortran, and Fortran is
probably an easier language to learn at the beginning. C is more
flexible and is standard on all Unix machines, but the advantages come
only in the kind of programming more common in Computer Science than
in Physics. C++ is now the fashionable, "object oriented" version of C.
Java is also available.
I will not discuss the instructions of either C or Fortran in this
document.
There are many books available.
The compilers we have on the Suns are
For both languages, the steps in writing and running a program are the
same. First you use an editor to create a file with instructions in
that language. The filename should end in .f or .c
or .cc or .java for
Fortran, C, C++, and java programs respectively. The program must then be
compiled,
using the f77, CC, or similar command.
Then it must be ``linked''
together with other functions that it uses, to produce an executable
program.
This is most conveniently done using a very sophisticated Unix utility
called make. A file usually called Makefile gives the
compile and link instructions. Unless someone has set you up with an
easy to use Makefile,
you will need to do some reading on make
before you can use it. One source is
/physics/doc/physics/programming/make.doc.
As programs usually need correcting before they will compile
correctly, the most efficient way to work on a program is to have the
file in an emacs buffer. When you are ready, type
<esc> x compile <ret>
and then correct (if necessary) the compile command. If you have a
good Makefile in place, it won't need correction, so just type
<ret> .
Emacs will open a second window, and tell you your errors,
if any. The command
Once you have a successful compilation and linking, you can execute
your program just by using its name (without the suffix) as a command.
Electronic mail is both very useful and overused, so I want to
encourage you to use it, but to do so in moderation.
There are a number of different programs that can be used to read or
send mail, which is unfortunate, because it means people have a harder
time interchanging expertise. We currently recommend using the
mailer of the Mozilla (or Netscape) browser.
CDE dtmail mailtool can be used as well as program Pine .
You can learn about e-mail setup details particular for our Department
from our e-mail setup web page .
In mozilla use HELP menu to learn about mail program
and EDIT-PREFERENCES meny to set it up. To do proper setup, you
will need to know
your user name, pop server name: pop.physics.rutgers.edu and
smtp server name: smtp.physics.rutgers.edu.
There is good documentation on the web for using Pine:
Sending mail is very useful. It is easier to convey precise information,
you don't wind up "playing phone tag", and you can keep a record of what
was said.
Don't go haywire with this newfound ability to communicate with
others, but use it reasonably. In particular, don't send mail to large
lists of people when you only really want to give the information to
a subset of that list - it is very annoying to the others.
The unix system has innumerable commands, which makes it confusing. To
help somewhat, it provides a short description of how to use each
command, which is available on the computer by giving the command
Some printed manuals can be found in the ARC terminal room and rooms
341, 383, and 241 in Serin. These are not to be removed, except for
immediate Xeroxing and return. Some information is available on the
computer in the directory /doc, but much of this is quite technical.
In principle, simpler stuff should appear in /doc/physics/intro,
but there is very little there yet except for a latex version of a previous
version of this document.
This document is an effort to start a web-based help facility for our users.
Information should be available about all the commonly used utilities on
our Sun systems. What we have so far is here.
There are many other things you might want to learn about.
It may be
useful to know the names of a few of these things which might be
useful. Some suggestions:
More introductory documents on Unix are available at other
Rutgers sites:
Using Unix: The Introduction .
Introduction
This short note is designed to be a very elementary introduction to UNIX computing
at the Physics Department. It covers only the most rudimentary things,
but it provides pointers to more information.
Logging on and off the computer
Logging on, or login
Password
physsun4% passwd
Old password: old-password...........
Type old password. It will not be shown. Follow
with <ret>
New password: new-password...........
Type your new password.
Follow with <
Retype new password: new-password
yellow pages entry changed on physsun5.rutgers.edu
Logging off
Don't leave yourself logged in!
X windows GUI
Using the keyboard
Files
more filename
You can see a list of the files you have by the command ls, which
shows most of the files in your directory. ls -a will show you
all
of them, but you don't want to know about the ones starting with a
period yet. ls -l will give you more information about each
file.
Editing
teach-emacs
Printing Text
lpr filename
You can check which print requests are not yet finished with the
command
lpq
This will tell you the job number of your print request. If you
realize that you shouldn't have printed it,
lprm job-number
will remove the request. Please be sure to pick up all your output,
whether you want it or not.
3w: Serin 346b
3t: Serin 383
2e: Serin 287
2w: Serin 246b
1w: Serin West, in corridor behind stockroom
arc: ARC 237
1s: Serin 103
lpr -P3w filename
will print filename on the third floor printer in Serin.
dvips paper.
Dvips also has many options to make it more flexible. For example
dvips -p4 -l10 -t landscape -P2e paper
will print only the pages from 4 to 10, inclusive, in landscape mode,
on the printer in Serin 277.
Programming
SUN compilers software contains full documentation locally (Following links will work only if you are reading this document from Physics Department Sun system).
There are other versions available if necessary.
cntl-x `
will position your cursor on the line with the first error.
Notice that is the open single quote, not an apostrophe, after the
ctrl-x. Correct the mistake
and type cntl-x ` repeatedly, correcting the errors as you go,
and then give the compile command again.
Mail
Getting help on computer commands
man command-name
The command man gets its name because it is giving you pages
of the manual.
These descriptions are not usually designed for the beginner, but you
should look
at them anyway if you are having trouble with a particular command.
Try man ls as an example to see both how
to use man and how
much you need to skip when doing so.
If you don't know the command name, but have a good keyword, try the
command apropos keyword.
For example,
apropos fortran
will give you a list of relevant commands and files, some mysterious
and some useful.
Other things
More detailed sources at Rutgers
Please send any comments on this page to
Richard Vaughn
Last modified: Wed Mar 29 12:15:01 EDT 2006