CSCI 141 GTA Instructions

Instructions For New Students (Transfer and non-Degree students)

 Getting started in UNIX

 Getting started in Windows NT

 Remote access to Unix

    SSH to hobbes.seas.gwu.edu

Getting ssh

Instructions On Getting Started In The Lab (on Windows NT)

• Opening a command shell
• Click the Start button
• Click run
• Type cmd and press ok


This should bring up a window in which commands can be typed
 

• Setting up path for java development kit
 
1.     In the command window type javac press enter.
2.     If the command goes through with message like


C:\>javac
  Usage: javac <options> <source files>
  where possible options include:
  -g                        Generate all debugging info
  -g:none                   Generate no debugging info
  -g:{lines,vars,source}    Generate only some debugging info
  -O                        Optimize; may hinder debugging or enlarge class file

  -nowarn                   Generate no warnings
  -verbose                  Output messages about what the compiler is doing
  -deprecation              Output source locations where deprecated APIs are us
ed
  -classpath <path>         Specify where to find user class files
  -sourcepath <path>        Specify where to find input source files
  -bootclasspath <path>     Override location of bootstrap class files
  -extdirs <dirs>           Override location of installed extensions
  -d <directory>            Specify where to place generated class files
  -encoding <encoding>      Specify character encoding used by source files
  -target <release>         Generate class files for specific VM version

    This means that java development kit is in your path.
 

    3.    If instead the message appears as


C:\>javac
The name specified is not recognized as an
internal or external command, operable program or batch file.

    This indicates that the java development kit is not yet in your classpath. Please notify TA/Instructor of this immediately so it can be permanenetly fixed.
    To fix temporarily,
                                a) Locate the javac program on your computer using Start-> Find -> Files or folders.
                                    Let us suppose it is in c:\jdk1.3\bin
                                b) Type in the command
                                 set PATH=%PATH%;c:\jdk1.3\bin and press enter
                                c) Try step 1 again. If it fails, the path has not been set correctly.
                                    If it works, it is temporary for the current command window only. Any other command windows opened later will require their
                                    path to be set again to access javac following steps a and b.
 

• Setting up the classpath

 

 
 
 
 
 
 
 

    In order to use class files located in a directory different than the current directory or to use class files that have been packaged into a single jar file, a classpath needs to be given to the javac or java programs. This can de done in ONE of two ways
 

1.    Dynamically using a classpath for a single run of javac or java. This is done using the -classpath switch.


                    e.g. javac -classpath c:\projects;c:\myalgs;. HelloWorld.java

      As can be seen, different directories are separated by the ';'separator in Windows. The '.' directory indicates to look for files in the current directory as well. This is especially important when the files to be compiled or run are in the current directory.
 

2.    Setting the CLASSPATH variable to be used by javac or java. (similar to setting the PATH variable)


                    This can be done in the command window by typing the command

set CLASSPATH=%CLASSPATH%;new_directories_to_be_added_separated_by_;

e.g. set CLASSPATH=%CLASSPATH%;c:\projects;c:\myalgs;.

Now this classpath can be used by javac or java without specifying the -classpath switch

e.g javac HelloWorld.java

Note: The set classpath is usable in the current command window only. Any other command windows that will be opened, will need to have their CLASSPATH set again.
 

• In order to verify the classpath at any point of time, type in the command window

 
echo %CLASSPATH% and press enter

If there is no output to the screen, that means that there is no classpath set at this point of time (or it was set incorrectly).
Instead if the output is like

C:\>echo %CLASSPATH%
"C:\Program Files\JavaSoft\JRE\1.3.1\lib\ext\QTJava.zip;."

This means that the classpath has been correctly set and is the above value.
 

• Note that in order to specify jar files in the classpath, the entire path as well as the name of the jar file needs to be present in the classpath
e.g. set CLASSPATH=%CLASSPATH%;c:\projects\MyGraphPackage.jar;.
• Running Emacs

 
Emacs can be run by clicking Start -> Programs -> GnuEmacs -> Emacs

Emacs is a text editor providing a graphical user interface. Emacs will be used for writing java programs over the semester. Most menu commands are similar to those in a regular text editor. Most of these commands can also be issued using the keyboard.
For a small tutorial on emacs, select Help-> Tutorial from the emacs menu bar or type Ctrl + H
 

• Compiling and running java programs using Emacs
 
Emacs, in the labs, have a Java Development Environment installed on them and hence can be easily used for java source code compilation and program execution. Once the program has been written, select  JDE from the menubar and clicking compile or run etc. A lot of Java specific commands are in the JDE and JAVA menus.

Instructions On Development Remotely Using Hobbes (unix)

Setting up path for java development kit

 
1.     At the command prompt type javac press enter.
2.     If the command goes through with message like


>javac
  Usage: javac <options> <source files>
  where possible options include:
  -g                        Generate all debugging info
  -g:none                   Generate no debugging info
  -g:{lines,vars,source}    Generate only some debugging info
  -O                        Optimize; may hinder debugging or enlarge class file

  -nowarn                   Generate no warnings
  -verbose                  Output messages about what the compiler is doing
  -deprecation              Output source locations where deprecated APIs are us
ed
  -classpath <path>         Specify where to find user class files
  -sourcepath <path>        Specify where to find input source files
  -bootclasspath <path>     Override location of bootstrap class files
  -extdirs <dirs>           Override location of installed extensions
  -d <directory>            Specify where to place generated class files
  -encoding <encoding>      Specify character encoding used by source files
  -target <release>         Generate class files for specific VM version

    This means that java development kit is in your path.
 

    3.    If instead the message appears as


>javac
The name specified is not recognized as an
internal or external command, operable program or batch file.

    This indicates that the java development kit is not yet in your classpath. Please notify TA/Instructor of this immediately so it can be permanenetly fixed.
    This requires changes to your .profile.
 

• Setting up the classpath

 

 
 
 
 
 
 
 

    In order to use class files located in a directory different than the current directory or to use class files that have been packaged into a single jar file, a classpath needs to be given to the javac or java programs. This can de done in ONE of two ways
 

1.    Dynamically using a classpath for a single run of javac or java. This is done using the -classpath switch.


                    e.g. javac -classpath ~/projects:~/myalgs:. HelloWorld.java

      As can be seen, different directories are separated by the ':'separator in Unix. The '.' directory indicates to look for files in the current directory as well. This is especially important when the files to be compiled or run are in the current directory.
 

2.    Setting the CLASSPATH variable to be used by javac or java. (similar to setting the PATH variable)


                    This can be done in the command window by typing the command

export CLASSPATH=$CLASSPATH:new_directories_to_be_added_separated_by_:

e.g. export CLASSPATH=$CLASSPATH:~/projects:~/myalgs:.

Now this classpath can be used by javac or java without specifying the -classpath switch

e.g javac HelloWorld.java

NOTE: The export command if typed into your .profile file will set your classpath permanently for every time you log in to hobbes.
 

• In order to verify the classpath at any point of time, type in the command window

 
echo $CLASSPATH

If there is no output to the screen, that means that there is no classpath set at this point of time (or it was set incorrectly).
Instead if the output is like

>echo $CLASSPATH
/home/student/hozefa/projects:/home/student/hozefa/myalgs:.

This means that the classpath has been correctly set and is the above value.
 

• Note that in order to specify jar files in the classpath, the entire path as well as the name of the jar file needs to be present in the classpath
e.g. export CLASSPATH=$CLASSPATH:~/projects/MyGraphPackage.jar:.

Remote Software Development (from HOME)

         Download Java Development Kit - JDK 2 v 1.3

        Emacs Text Editor

            Emacs Description

            Emacs Windows Download

                 Note: If you are trying to install Emacs on a unix or linux system, chances are emacs is already installed.
                          Check by typing emacs at the shell prompt. If not, download from ftp://ftp.uu.net/archive/systems/gnu/emacs/emacs-20.7.tar.gz

             Utilities to extract files in windows

    Java Development Environment for Emacs

            Extract the following files depending on your operating system

                 JDE in Emacs for Windows

                    Note: For Windows unzip this file to your c:\

JDE in Emacs for Unix/Linux