DOS - My First Batch File

You have heard a lot about DOS and batch files but you just can’t figure out how to create one yourself?

Learn here how to create your first DOS patch program in a few easy steps.

 

1      General. 1

2      Create a DOS batch - "hello.bat". 1

3      Execute a DOS batch - "hello.bat". 1

4      Summary. 1

5      How to continue from here. 2

 

 

1        General

 

DOS batch files are written in plain text.  Any text editor that can store plain text can be used to create a new DOS batch file.

DOS batch files use the file extension .bat or .cmd.

In our simple example we will use Notepad to create a batch file right on the desktop.

The Notepad program is available on all Windows platforms.

2        Create a DOS batch - "hello.bat"

Description

Use Notepad to create a new file called hello.bat on your desktop.  Add the code shown below to the file and save it.

This can be done step by step as follows:

Do

·          In the Start menu click: Programs – Accessories – Notepad

 

The Notepad program starts up showing an empty document with the title: “Untitled - Notepad”

Do

·          In the Notepad menu click:  File – Save As

 

The Save As dialog shows up

Do

·          In the Save As dialog use the Save in drop down box to select: Desktop

·          In the File name field overwrite the file name by typing: hello.bat

·          Click: Save

 

The Save As dialog will close.  Notepad shows an empty document with the title: “hello.bat - Notepad”.  A new icon with the name hello.bat appears on the Desktop.

Do

·          Type or copy/paste the following code into notepad:

Code

@echo Hello world.

@pause

Do

·          In the Notepad menu choose: File - Save

Congrats

Done!  Your fist DOS batch file is ready to run.

3        Execute a DOS batch - "hello.bat"

Do

·          Minimize all windows and locate the icon called hello.bat on your desktop.

·          Double click the hello.bat icon

 

A new window will open showing the following message:

 

Hello world.

Press any key to continue . . .

Do

·          Press any key, e.g. Space

 

The window will close.

Congrats

You just executed your first DOS batch.

4        Summary

 

When double clicking hello.bat on the desktop the file was passed to the DOS command processor.  Independent from the executed batch file the command processor will always open a new window.  This window will close when the command processor finished executing the batch file.

The command processor executes the commands listed in the batch file line by line.  Commands in the batch file can instruct the command processor to interact with the user, i.e. to show some text output in the window or to wait for keyboard input.

If not instructed differently the command processor echoes each command from the batch to the window before executing it.  This can be useful for testing and debugging but is usually annoying in the final version of the batch file and because of this omitted in the example by having the ‘@’ sign in front of each line.

Inside Hello.bat

The first line instructs the command processor to show the text: “Hello World.”

The second line instructs the command processor to pause till the user hits a key on the keyboard.

After pressing a key the batch file finishes and the command processor will close the window.

Lesson learned

The simple example teaches three features of the command processor.

·          The echo command displays text on the screen.

·          The pause command causes the command processor to pause until the user hits a key on the keyboard.

·          The ‘@’ sign at the beginning of a line prevents the command processor to echo the line on the screen while executing.

Tip

To turn off the echoing of commands for the whole batch file use the “@echo off” command as first command in the batch file.  The hello.bat example can be rewritten as follows in order to avoid an ‘@’ in front of each line:

Code

@echo off

echo Hello world.

pause

5        How to continue from here

 

Now you have your first DOS batch running and you may want to know what all you can use it for.

A whole group of predefined DOS commands is available with your operating system that can be used to enhance this simple example and make a useful application out of it.

To list all predefined dos commands open a command console and type help.

This can be done as follows:

Do

·          In the Start menu click: Run

 

The Run dialog box opens

Do

·          In the Open edit box type: cmd.exe

 

The command console opens reporting the windows version.  A blinking cursor shows up.

Do

·          Enter: help and hit the  Enter key

 

A list of predefined DOS commands with a brief description shows up.  Followed by the blinking curser waiting for more input.

Do

·          Pick any dos command from the list.  Type help and the DOS command to get more information about it’s usage.  I.e. type: help echo and hit Enter to get the details about the echo command

Example

C:\>help echo

Displays messages, or turns command-echoing on or off.

 

  ECHO [ON | OFF]

  ECHO [message]

 

Type ECHO without parameters to display the current echo setting.

 

C:\>

Lesson learned

There is a whole list of predefined DOS commands available.  Those DOS commands can be combined in a batch file in order to build a useful DOS batch application.