What you absolutely have to know to do anything at a command prompt

it's absolutely all about paths, relativly speaking

Websters Desk Dictonary defines path as "1. A way or track made by footsteps. 2. A course: route". A path in computerese is a related concept, but only if you think of yourself as a little duck that waddles along those dotted lines you see in Windows Explorer. The dotted lines are all the possible paths.

Absolute Paths

Absolute paths are absolute because no mater where you are, the directions start at the root of the drive. In DOS and Windows, you specifiy this by typing the drive letter at the begining. The following are examples of absolute paths:

C:\Windows
A:\homework\cis18a\chapter1
S:\

Relative Paths

A realtive path is realtive to your current position. It tells the duck to start wherever it's currently standing and follow directions from there. To use a relative path you need to know where you started and everything in between your startpoint and your endpoint. Relative paths are most useful when just want to move up or down a directory. (moving around is the next) Examples of relative paths include:

Favorite\Links (relative to C:\Windows)
cis18a\chapter1\partA (realtive to A:\homework)

The Path

The Path is the value in the path environmental variable. It holds a list of places that the windows duck should look for programs (executables) in. Why this is important will be discused in the executing commands section. Each time you open a DOS prompt, it copies (or inherits) the value of path from the global (master) set to it's own. You can change the global path by editing autoexe.bat. You can also change each individual DOS window's path by setting path equal to a new value on the comand line. Here are a few examples of setting the path:

path=C:\myprograms
path="C:\My Programs" (NOT the same place)
path="C:\My Programs";%path%; (tells the computer to look in C:\My Programs, and then look in all the places that it used to look)
path=%path%;"C:\My Programs";"A:\homework"; (tells the computer to add C:\My Programs and A:\homework to the list of places to look for executable files)

Moving yourself around

At every command prompt I have ever seen, cd will Change the Directory that your working in. It makes the little duck fly. cd takes one argument - the path of the directory you would like to be in. Using two periods (..) as the argument is a shortcut to go 'up' one directory - and another example of a realtive path.

Executing commands (aka running programs)

To execute a command (or run a program), you just type the command or programs name. To windows, a command and a program are pretty much the same thing. The .exe at the end of every program name is optional. If the program takes arguments, you must know what they are and type them after the command name. DOS always looks in the folder that your currently in before looking along the path. So if your in the same directory as the program you want to run, just type it's name. if your not, type the path (and the program name) that will tell windows where to find it. If the program is on the path, then you don't need to do all that typing. You can just type the name of the program from anywhere. examples of ways to run programs:

bin\javac (from the jdk folder)
javac (from anywhere if it in the path)
javac.exe (from the folder where javac.exe is located)
C:\jdk\bin\javac.exe (from anywhere)

Looking at the Stuff Stored in the directory

In MS-DOS, typing dir will show you what is in the directory that you are in. If you want to view files in a differnt directory typ dir, a space, and the path of the directory you want see the contents of. This is an example of using a command (running a program) that takes arguments.