On Windows, we will use something called an SSH client. An SSH client lets you interact with another computer over the Internet. SSH clients usually look old skool, like something they would have used in the 80s. Why? They allow you to interact with a program on another computer called a shell. You can also run graphical programs on those computers through your SSH client, but that's for another time.
The Windows machines in the labs come with Secure Shell, which isn't a very good SSH client. Instead, you should download PuTTY. Just putty.exe, will suffice for our purposes. Here's a short list on how to get PuTTY up and running.
The linux machines in the department come pre-installed with all of the tools you'll need to work on the 351 projects. In addition, things are set up so that your files are in the exact same places as on attu. You won't need to do any special setup on Linux. Just click Applications at the top, mouse to Accessories, and click Terminal.
Occasionally, you will need to access attu from your linux machine. Attu is a powerful computer sitting in the CSE building that is ready to run your work, except that it has no screen. It runs linux, and can only be accessed over the network. Anybody with a CSE account can use attu. Accessing attu is the same as accessing attu on your Mac OS X computer or home linux computer. First, open a Terminal:
Now that you have a terminal up, type:
ssh <your CSE username>@attu.cs.washington.edu
Press enter. If prompted about a server key, type yes and press Enter. When prompted, enter your Kerberos password and push Enter. Like PuTTY, it won't look like you're typing. This is done on purpose :)
At home, you'll need to access attu. Follow the instructions in the lab writeup to copy and uncompress the lab on attu. See the section on Editing Files for information on how to quickly edit files from home.
First off, folders are a fancy word that Microsoft invented to make comptuers seem more human. While folders are great, they're called directories on linux.
The first thing that most new users shifting from Windows will find confusing is navigating the Linux filesystem. The Linux filesystem does things a lot more differently than the Windows filesystem.
For starters, there is only a single hierarchal directory structure. Everything starts from the root directory, represented by '/', and then expands into sub-directories. Where DOS/Windows had various drives (C:, D:, etc) and then directories under those partitions, Linux places all the drives under the root directory by 'mounting' them under specific directories. Closest to root under Windows would be C:.
Another point likely to confuse newbies is the use of the frontslash '/' instead of the backslash '\' as in DOS/Windows. So c:\windows\system would be /c/windows/system. Well, Linux is not going against convention here. Unix has been around a lot longer than Windows and was the standard a lot before Windows was. Rather, DOS took the different path, using '/' for command-line options and '\' as the directory separator.
To keep people from stepping on everybody's toes, everybody has one
folder or directory that they can write and make changes to. This is
called your "home directory". On any unix system, you can
refer to the home directory with a tilde, so a folder called frogs
inside of your home directory would have a path like:
~/frogs
When you run a command, your shell will replace ~ with the path to your home directory. If you want to know what that is or how to manipulate the shell, read the next section on basic unix commands.
attu4% mkdir mydir attu4% ls mail mydir attu4% cd mydir attu4% pwd /homes/iws/areusch/mydir attu4% exitIn the above (the things within the quotation marks are commands to type, don't type the quotation marks themselves):
The shell is the program where you type in commands. There are different shell programs, which are all similar but have different rules and features. For sake of uniformity, we will use a shell called "bash" but it's likely that your account is set-up such that when you create an terminal the shell it uses is "csh". You can change this for the time being or once and for all. We strongly recommend the latter, but we'll explain the former first to help you understand what is going on.
For the time being: Type
attu4% bashNow you may have a different looking prompt (such as bash-3.00$). Otherwise at this point you will not notice any differences, but that's only because you don't know any differences between bash and csh. When you type
bash-3.00$ exityou'll be back to the shell you were running when you typed bash. That is, you started running a different shell and when you exited, you just went back to the outer one.
Once and for all: You could type bash every time you create an terminal, but that's a pain and you could get confused if you forget. So you can tell the operating system once and for all that for your account, the "first shell" for every terminal should be bash. From any prompt, type:
chsh -s /bin/bashYou are running the "change shell" program and specifying that your new shell can be found at /bin/bash. It's almost that simple:
First thing's first: What I say here is not final. There is a ton of debate on this.
For this course, you can use something as simple as Notepad. However, we strongly recommend something better. Here is a list of things, by OS, that we recommend:
When working at home, you'll notice that you need to have your files on attu in order to compile and test your work. You can edit with nano, pico, emacs, or vi on attu, just by typing those commands and pressing Enter. However, depending on the latency between your computer and attu (i.e. the time that goes by before you press a key, attu receive the key, and tells your computer what to print on the screen in response), this might not be practical.
A better way is to download the lab to your hard drive, then use a Windows text editor to make changes. After that, you'll need a program called WinSCP to copy your changes to attu and compile them.
When you run a command like btest on attu, you may see something like the following:
Gives 1942614435[0x73c9f1a3]. Should be 204869213[0xc360e5d] ... 9 total errors for function abs Test abs score: 0.00/4.00 Test addOK(-2147483648[0x80000000],-2147483648[0x80000000]) failed. Gives -2147483648[0x80000000]. Should be 0[0x0] Test addOK(-2147483648[0x80000000],2147483647[0x7fffffff]) failed. Gives -2147483648[0x80000000]. Should be 1[0x1] Test addOK(-2147483648[0x80000000],-3[0xfffffffd]) failed. Gives -2147483648[0x80000000]. Should be 0[0x0] Test addOK(-2147483648[0x80000000],811666840[0x30610d98]) failed. Gives -2147483648[0x80000000]. Should be 1[0x1] Test addOK(-2147483648[0x80000000],-2147483647[0x80000001]) failed. Gives -2147483648[0x80000000]. Should be 0[0x0] ... 321 total errors for function addOK Test addOK score: 0.00/3.00 Overall correctness score: 14.00/36.00 1541 errors encountered.
What happened to the first part of it? Answer: it scrolled up past the top of your terminal. You'll have to tell attu you want to save all of that output somewhere, like this:
./btest >feedback_filename
If you run btest (or any command) like this, linux will save its output in the file called "feedback_filename" for you to view later in your favorite text editor (see above section).
Alternatively, if you just want to see the output once, try it this way:
./btest | less
You can then use the up/down arrow keys to move around your output
in a quick n dirty fashion. Use the 'q' key to quit. Be aware: Once
you quit, the output is gone for good! But, luckily for you, you
can just re-run btest to get it back. You can also use less to view
the output from your saved file, like less feedback_filename.
Not everything is perfect, sadly :(. One of those is our build
system. Though it is unlikely, the rule of thumb when running the make
command is:
If something really doesn't look like it's running right, do a
make clean, then a make and try it
again.
To save time, make and gcc will save some of the computation required to build your software. However, at times, this can become corrupt and interfere with changes you're making.