Compiling on the Command line with Java SDK

Primary SDK tools

The primary Java SDK tools, which can be accessed from a command prompt/shell, are:

  javac             // the compiler
  java              // loader/interpreter

Windows versions of these filenames would be:

  javac.exe
  java.exe

These commands (discussed below) will work in any of the following command-line prompts, as long as the SDK is installed:

Unix (like in the CS accounts)
Windows command prompt (DOS prompt)
Mac OS X Terminal prompt (which uses Unix)

Using the `javac` command

Source code files will end in .java
To compile a source code file, the command format is:
```
  javac filenmame
```

Examples:

  javac Example1.java
  javac MyProg.java
  javac Arithmetic.java

The result will be a file (or files) ending in .class
- For every class in a source code file, a full .class file is created

Using the `java` command

To run a java program, use the java command. Basic format:
```
  java main-class
```
In this format, substitute (for main-class above) the name of the class that contains the main() method that is the start of your desired program

Examples:

  java Arithmetic        // runs main() in class Arithmetic
  java Fred              // runs main() in class Fred

Working in a CS account on linprog

Everybody enrolled in this course is allowed to sign up for a temporary Computer Science department account. Instructions are here:
- CS Account Information
You'll want to download SSH software for this, if you don't already have it. See the account info page for download link
Once you register for an account, you should log into linprog.cs.fsu.edu if you want to use the SDK tools from your CS account login. linprog has the latest Java SDK installed
This machine is running Linux, so you would need to be familiar with basic unix commands (like creating files, directories, moving around, etc). Bob Myers created a basic unix tutorial here, which has just enough to show you how to get around:
- Bob Myers' Basic Unix Tutorial
This environment is fine for console applications. It will not be as good when we get to GUI applications (although can be done through tunnelling)

Working on a Windows PC on the command line

Select "Start", then "Run", then type "cmd", to open a command prompt
Use "cd" command to change directories (similar to unix command)
Use "dir" to see a directory listing
Use javac and java commands as illustrated earlier
Recommend using a Windows-based text-editor to actually edit the files. Wordpad is fine for this purpose.
You will probably need to set the "PATH" variable. See below

Setting the PATH environment variable

To run a program from the command line from any directory, you either have to type its full location and name every time (annoying) or set its location in your "PATH". To set the path...

You'll need to know where your Java SDK was installed. Usually it goes (by default) into a folder like this:
```
  C:\Program Files\Java\jdk1.8.0_16
```
Make sure you take note of the exact folder name and location
From the Start menu, right-click "My Computer", and pick "Properties"
Click the "Advanced" tab
Click the "Environment Variables" button
At the top of the window, where it says "User variables for ...." look to see if there is a "PATH" variable in the window. If there is, highlight it and click Edit. If there isn't, click "New"
Make sure Variable name says, "PATH". Under "Variable value", add in the expression that matches where the java installation is, along with "\bin". Example:
```
  C:\Program Files\Java\jdk1.8.0_16\bin
```
IF there's already something in the PATH variable, separate it from the new item (above) with a semi-colon. Example:
```
 C:\Program Files\SSH Communications Security\SSH Secure Shell;C:\Program Files\Java\jdk1.8.0_13\bin
```
Changes won't apply until you close the "cmd" prompt and launch it again