DOS Command Common Sense _dos/bat

Overview of DOS
DOS (disk operating system) is a widely used disk operating system, even the current popular windows9x/me system is based on it.

There are two common DOS types: IBM's Pc-dos and Microsoft's MS-DOS, which have the same functional, command-use format, and we often use MS-DOS.

Since the advent of DOS in 1981, the version has been constantly updated, from the initial DOS1.0 to the latest DOS8.0 (Windows Me system), pure DOS The highest version is DOS6.22, and the new version of DOS is provided by Windows systems and does not exist alone. The following explanation uses DOS for the WINDOWS98 4.10.2222A DOS7.0 system.

dos Basics
1 dos component Dos is divided into Core launcher and command program two parts. The core boot program for

DOS has the boot system boot program, IO. SYS, MSDOS. SYS and Command.com. They are the most basic parts of a DOS system and can be started with their systems.

But there is no starting program, DOS as a character of the operating system, the general operation is through the command to complete. Dos commands are divided into internal commands and external commands. Internal commands are some of the most commonly used and space-limited command programs, such as Dir, CD, etc., which exist in the Command.com file and are loaded into memory at system startup to facilitate invocation. Some other external commands exist in a separate executable file and are only transferred to memory when used.


2) dos start
If you install WIN98, hold down CTRL while the computer is up, and the Start menu appears. Select 5 "Command Prompt only" to enter the DOS mode.

At present our common operating system has Windows 9x/me,nt,2000 and so on, all are the visual interface. The operating system used by people before these systems is the DOS system. The DOS system is no longer available to anyone, but the DOS command still exists in the Windows system we use. Most DOS commands have become visual interfaces in Windows, but some advanced DOS commands are still being implemented in a DOS environment. So learning command line is very necessary for us to operate Windows system skillfully.

Different operating systems have to enter the command line interface with different commands.
Type command in the run program in the Win9x/me Start menu to enter the command-line interface.
In the Start menu of Win2000/nt, run the "quot;cmd" command, which allows you to enter the command line interface.
The following DOS commands I've talked about can be executed in the Windows Me operating system.

So, how do we get to the command line window? The
start--〉 run--〉 Type command Command--〉 carriage return
enters the command-line operation interface (DOS window) and can only be operated with the keyboard in a DOS window.
in DOS by entering the English command plus the ENTER key in this way to execute the program. The

3 dos system prompt
will display "c:>" and a flashing cursor, which is the DOS system prompt, which represents the current letter and directory. We can enter "[Letter]:" To make the conversion, such as "A:", "E:". Note that the input letter must be present.


4) files and directories
The data in the computer is mostly stored in file form, It can also be said that dos in the form of files to manage data. A
file is a collection of related data that is aggregated together to form a file. Each file has a file name, which consists of a main file name and a suffix name, separated by a small dot in the middle. DOS6.22 and its previous versions support only 8-character primary and 3-character suffix names, and 128-character primary file names and suffix names can be supported from Windows 95 DOS7.0. Letters, Chinese characters, numbers, and some special symbols such as "!, @, #" can be used as file names, but cannot have "/, \, |,:,?" and other symbols.

Usually we can see the file's type by its suffix name, for example:

Suffix name	File type
Exe	Executable Program Files
Com	Executable Command file
BAT	Executable Batch File
Txt	Text file
Dat	Data files
Bak	Backing up files

wildcard . The so-called wildcard character, is "? "and" * ", which can be used in place of certain characters in the filename. "？ "represents a valid character or null character, such as" AB? D.EXE "file can represent" ABCD. EXE "," ABDD. EXE "," Abzd. EXE "and so on. The

and "*" represent several characters, such as "*. Bat "represents all files in the current directory that have a suffix named" bat. "
DOS manages the disk as a directory tree, where the directory is equivalent to a folder in Windows. Like a folder, a table of contents is a layer of the form of a tree. The directory at the bottom of a letter is the root directory, and the directory under the root directory is called its subdirectory, the root directory is represented by "\", and the top level of the directory is "..." Said. We can find a file or directory through the path, like the address, so that users can easily and accurately search. For example, "C:\Windows\Command\deltree.exe" is a path to a file.

In the same directory, files or directories with the same name are not allowed.