CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [244]
After shaking hands with IBM representatives, Bill Gates hurriedly began to search for an OS based on the Intel 8086 processor. He found a primitive OS called Quick-and-Dirty Operating System (QDOS), which was written by a one-man shop, and he purchased it for a few thousand dollars. After several minor changes, Microsoft released it as MS-DOS (Microsoft Disk Operating System) version 1.1. Although primitive by today’s standards, MS-DOS 1.1 could provide all of the functions an OS needed. Over the years, MS-DOS went through version after version until the last Microsoft version, MS-DOS 6.22, was released in 1994. Microsoft licensed MS-DOS to PC makers so they could add their own changes and then rename the program. IBM called its version PC-DOS.
DOS used a command-line interface. You typed a command at a prompt, and DOS responded to that command. When Microsoft introduced Windows 95 and Windows NT, many computer users and techs thought that the command-line interface would go away, but techs not only continued to use the command line, they also needed it to troubleshoot and fix problems. With Windows 2000, it seemed once again that the command line would die, but again, that just didn’t turn out to be the case.
Finally recognizing the importance of the command-line interface, Microsoft beefed it up in Windows XP and then again in Windows Vista. The command line in Windows XP and in Vista offers commands and options for those commands that go well beyond anything seen in previous Microsoft operating systems. This chapter starts with some essential concepts of the command line and then turns to more specific commands.
Practical Application
Deciphering the Command-line Interface
So how does a command-line interface work? It’s a little like having an Instant Message conversation with your computer. The computer tells you it’s ready to receive commands by displaying a specific set of characters called a prompt.
Computer: Want to play a game?
Mike: _
You type a command and press ENTER to send it.
Mike: What kind of game?
Computer: _
The PC goes off and executes the command, and when it’s finished, it displays a new prompt, often along with some information about what it did.
Computer: A very fun game...
Mike: _
Once you get a new prompt, it means the computer is ready for your next instruction. You can give the computer commands in the GUI of Windows as well, just in a different way, by clicking buttons and menu options with your mouse instead of typing on the keyboard. The results are basically the same: you tell the computer to do something and it responds.
When you type in a command from the command line, you cause the computer to respond. As an example, suppose you want to find out the contents of a particular folder. From the command line, you’d type a command (in this case DIR, but more on that in a minute), and the computer would respond by displaying a screen like the one in Figure 15-1.
Figure 15-1 Contents of C: directory from the command line
In the Windows GUI, you would open My Computer or Computer and click the C: drive icon to see the contents of that directory. The results might look like Figure 15-2, which at first glance isn’t much like the command-line screen; however, simply by choosing a different view (Figure 15-3), you can make the results look quite a bit like the command-line version, albeit much prettier (Figure 15-4). The point here is that whichever interface you use, the information available to you is essentially the same.
Figure 15-2 Contents of C: in Computer—Icon view
Figure 15-3 Selecting Details view in Computer