Creating Command Line Scripts in Windows

Creating Command Line Scripts

Command line scripts are text files containing the commands you want to execute. These are the same commands you would normally type into the Windows command shell. However, rather than enter the commands each time you want to use them, you create a script to store the commands for easy execution.

Because scripts contain standard text characters, you can create and edit scripts using a standard text editor, such as Notepad. When you enter commands, be sure to place each command or group of commands that should be executed together on a new line. This ensures proper execution of the commands. When you have finished creating a command-line script, save the script file using the .bat or .cmd extension. Both extensions work with command-line scripts in the same way. For example, if you wanted to create a script to display the system name, Windows version and IP configuration, you could enter these three commands into a file called SysInfo.bat or SysInfo.cmd:

hostname

ver

ipconfig -all

Once you save the script, you can execute it as if it were a Windows utility; simply type the name of the script in a command shell and press Enter. When you do this, the command shell reads the script file and executes its commands one by one. It stops executing the script when it reaches the end of the file or reads an EXIT command. For the example script, the command line would display output similar to Listing 3-1.

Listing 3-1: Output of Sample Script

C:\>hostname

mailer1






C:\>ver

Microsoft Windows [Version 5.2.3790]






C:\>ipconfig -all 

Windows IP Configuration

Host Name . . . . . . . . . . . . : mailer1

Primary Dns Suffix  . . . . . . . : adatum.com

Node Type . . . . . . . . . . . . : Unknown

IP Routing Enabled. . . . . . . . : No

WINS Proxy Enabled. . . . . . . . : No

DNS Suffix Search List. . . . . . : adatum.com






Ethernet adapter Local Area Connection:






Connection-specific DNS Suffix  . : 

Description . . . . . . . . . . . : Intel(R) PRO/100 VE Network

Connection

Physical Address. . . . . . . . . : X0-EF-D7-AB-E2-1E

DHCP Enabled. . . . . . . . . . . : No

IP Address. . . . . . . . . . . . : 192.168.10.50

Subnet Mask . . . . . . . . . . . : 255.255.255.0

Default Gateway . . . . . . . . . : 192.168.10.1

DNS Servers . . . . . . . . . . . : 192.168.10.155

If you examine the listing, you’ll see that the command prompt and the actual commands are displayed as well as the output of the commands themselves. The reason for this is that the command shell does some extra work behind the scenes while executing scripts in the default processing mode. First, the command shell displays the command prompt. Next, it reads a line from the script, displays it, and then interprets it. If the command shell reaches the end of the file or reads an EXIT command, execution stops. Otherwise, the command shell starts this process all over again by displaying the prompt and preparing to read the next line in the script.

Although the default processing mode with command echoing on can be useful for troubleshooting problems in scripts, you probably don’t want to use this display mode with scripts you’ll use regularly. Fortunately, you can change the default behavior by turning command echo off, as I’ll show you later in the chapter in the section titled “Managing Text Display and Command Echoing.”