Overview of DOS
DOS (Disk Operating System) is a very widely used disk operating system. Even the currently popular Windows 9x/ME systems are based on it.
There are two common kinds of DOS: IBM's PC-DOS and Microsoft's MS-DOS. Their functions, commands, and usage formats are the same. The one we commonly use is MS-DOS.
Since DOS first came out in 1981, its versions have been continuously updated, from the original DOS 1.0 up to the latest DOS 8.0 (the Windows ME system). The highest version of pure DOS is DOS 6.22. Newer DOS versions after that are all provided by Windows systems and do not exist independently. The DOS used in the explanations below is the DOS 7.0 system of Windows 98 4.10.2222A.
Basic knowledge of DOS
1）The composition of DOS
DOS is divided into two parts: the core boot programs and the command programs.
The core boot programs of DOS include the Boot system bootstrap program, IO.SYS, MSDOS.SYS, and COMMAND.COM. They are the most basic parts that make up the DOS system. With them, the system can boot.
But having only the boot programs is still not enough. Since DOS is a character-based operating system, ordinary operations are generally completed through commands. DOS commands are divided into internal commands and external commands. Internal commands are commonly used command programs that do not take up much space, such as dir and cd. They exist in the COMMAND.COM file and are loaded into memory when the system starts for easy calling. Other external commands exist as separate executable files and are loaded into memory only when used.
(A little knowledge: there are two kinds of executable program files, *.COM and *.EXE. Generally speaking, *.EXE files are software executable programs, while *.COM files are command programs.)
2）Starting DOS
If you have WIN98 installed, hold down Ctrl when the computer starts up. When the startup selection menu appears, choose 5 "Command Prompt Only" to enter DOS mode.
At present, the operating systems we commonly use include windows 9x/Me, NT, 2000, etc., and all of them have graphical interfaces. Before these systems, the operating system people used was DOS. Hardly anyone uses DOS systems now, but DOS commands still exist in the Windows systems we use. Most DOS commands have already turned into graphical interfaces in Windows, but some advanced DOS commands still need to be executed in a DOS environment. So learning the command line is still very necessary if we want to operate Windows skillfully.
Different operating systems use different commands to enter the command prompt interface.
In the Run program in the Start menu of Win9x/Me, type the "command" command to enter the command prompt interface.
In the Run program in the Start menu of Win2000/NT, type the ?quot;cmd" command to enter the command prompt interface.
The DOS commands I talk about below can all be executed in the Windows Me operating system.
So, how do we enter the command line window?
Start——〉Run——〉type the command command——〉press Enter
This takes you into the command-line operating interface (DOS window). In the DOS window, you can only operate with the keyboard.
In DOS, programs are executed by entering an English command and pressing Enter.
3）The DOS system prompt
After DOS starts, it will display "C:>" and a blinking cursor. This is the DOS system prompt. It shows the current drive letter and directory. We can enter " :" to switch, such as "A:" or "E:". Note that the drive letter you enter must actually exist.
(A little knowledge: drive letters go from A to Z. Usually drives A and B are floppy drives, hard disk drive letters start from C, and the CD-ROM drive letter is the last one.)
4）Files and directories
Most data in a computer is mainly stored in the form of files. It can also be said that DOS manages data in the form of files.
A file is a collection of related data. A number of pieces of data gathered together make up a file. Each file has a filename. A filename consists of two parts, the main filename and the extension, separated by a dot in the middle. DOS 6.22 and earlier support at most an 8-character main filename and a 3-character extension, while starting from DOS 7.0 of Windows 95, main filenames and extensions of up to 128 characters are supported. Letters, Chinese characters, numbers, and some special symbols such as "!、@、#" can all be used as filenames, but symbols such as "/、\、|、:、?" cannot.
Usually we can tell a file's type from its extension, for example:
Extension File type
EXE Executable program file
COM Executable command file
BAT Executable batch file
TXT Text file
DAT Data file
BAK Backup file
To make operation more convenient, DOS also allows the use of wildcard characters. The so-called wildcard characters are the two symbols "？" and "*". They can be used to replace certain characters in filenames. "？" represents one valid character or an empty character. For example, the file "AB?D.EXE" can represent "ABCD.EXE", "ABDD.EXE", "ABZD.EXE", etc.
"*" represents several characters. For example, "*.BAT" represents all files in the current directory whose extension is "BAT".
DOS manages disks in the form of a directory tree. The directories here are equivalent to folders in Windows. Like folders, directories are also layered one by one, forming a tree structure. In one drive, the lowest-level directory is the root directory, and the directories under the root directory are all called its subdirectories. The root directory is represented by "\", and the directory one level above a directory is represented by "..". We can locate a file or directory by its path. A path is like an address, allowing users to find it conveniently and accurately. For example, "C:\Windows\Command\deltree.exe" is the path of a file.
In the same directory, files or directories with the same name are not allowed to exist.
DOS (Disk Operating System) is a very widely used disk operating system. Even the currently popular Windows 9x/ME systems are based on it.
There are two common kinds of DOS: IBM's PC-DOS and Microsoft's MS-DOS. Their functions, commands, and usage formats are the same. The one we commonly use is MS-DOS.
Since DOS first came out in 1981, its versions have been continuously updated, from the original DOS 1.0 up to the latest DOS 8.0 (the Windows ME system). The highest version of pure DOS is DOS 6.22. Newer DOS versions after that are all provided by Windows systems and do not exist independently. The DOS used in the explanations below is the DOS 7.0 system of Windows 98 4.10.2222A.
Basic knowledge of DOS
1）The composition of DOS
DOS is divided into two parts: the core boot programs and the command programs.
The core boot programs of DOS include the Boot system bootstrap program, IO.SYS, MSDOS.SYS, and COMMAND.COM. They are the most basic parts that make up the DOS system. With them, the system can boot.
But having only the boot programs is still not enough. Since DOS is a character-based operating system, ordinary operations are generally completed through commands. DOS commands are divided into internal commands and external commands. Internal commands are commonly used command programs that do not take up much space, such as dir and cd. They exist in the COMMAND.COM file and are loaded into memory when the system starts for easy calling. Other external commands exist as separate executable files and are loaded into memory only when used.
(A little knowledge: there are two kinds of executable program files, *.COM and *.EXE. Generally speaking, *.EXE files are software executable programs, while *.COM files are command programs.)
2）Starting DOS
If you have WIN98 installed, hold down Ctrl when the computer starts up. When the startup selection menu appears, choose 5 "Command Prompt Only" to enter DOS mode.
At present, the operating systems we commonly use include windows 9x/Me, NT, 2000, etc., and all of them have graphical interfaces. Before these systems, the operating system people used was DOS. Hardly anyone uses DOS systems now, but DOS commands still exist in the Windows systems we use. Most DOS commands have already turned into graphical interfaces in Windows, but some advanced DOS commands still need to be executed in a DOS environment. So learning the command line is still very necessary if we want to operate Windows skillfully.
Different operating systems use different commands to enter the command prompt interface.
In the Run program in the Start menu of Win9x/Me, type the "command" command to enter the command prompt interface.
In the Run program in the Start menu of Win2000/NT, type the ?quot;cmd" command to enter the command prompt interface.
The DOS commands I talk about below can all be executed in the Windows Me operating system.
So, how do we enter the command line window?
Start——〉Run——〉type the command command——〉press Enter
This takes you into the command-line operating interface (DOS window). In the DOS window, you can only operate with the keyboard.
In DOS, programs are executed by entering an English command and pressing Enter.
3）The DOS system prompt
After DOS starts, it will display "C:>" and a blinking cursor. This is the DOS system prompt. It shows the current drive letter and directory. We can enter " :" to switch, such as "A:" or "E:". Note that the drive letter you enter must actually exist.
(A little knowledge: drive letters go from A to Z. Usually drives A and B are floppy drives, hard disk drive letters start from C, and the CD-ROM drive letter is the last one.)
4）Files and directories
Most data in a computer is mainly stored in the form of files. It can also be said that DOS manages data in the form of files.
A file is a collection of related data. A number of pieces of data gathered together make up a file. Each file has a filename. A filename consists of two parts, the main filename and the extension, separated by a dot in the middle. DOS 6.22 and earlier support at most an 8-character main filename and a 3-character extension, while starting from DOS 7.0 of Windows 95, main filenames and extensions of up to 128 characters are supported. Letters, Chinese characters, numbers, and some special symbols such as "!、@、#" can all be used as filenames, but symbols such as "/、\、|、:、?" cannot.
Usually we can tell a file's type from its extension, for example:
Extension File type
EXE Executable program file
COM Executable command file
BAT Executable batch file
TXT Text file
DAT Data file
BAK Backup file
To make operation more convenient, DOS also allows the use of wildcard characters. The so-called wildcard characters are the two symbols "？" and "*". They can be used to replace certain characters in filenames. "？" represents one valid character or an empty character. For example, the file "AB?D.EXE" can represent "ABCD.EXE", "ABDD.EXE", "ABZD.EXE", etc.
"*" represents several characters. For example, "*.BAT" represents all files in the current directory whose extension is "BAT".
DOS manages disks in the form of a directory tree. The directories here are equivalent to folders in Windows. Like folders, directories are also layered one by one, forming a tree structure. In one drive, the lowest-level directory is the root directory, and the directories under the root directory are all called its subdirectories. The root directory is represented by "\", and the directory one level above a directory is represented by "..". We can locate a file or directory by its path. A path is like an address, allowing users to find it conveniently and accurately. For example, "C:\Windows\Command\deltree.exe" is the path of a file.
In the same directory, files or directories with the same name are not allowed to exist.
