How to manually create a device node and write the main commands and parameters

There are many ways to do this, but here are a few simple ones:

1。Open Notepad, enter the batch process**, click "File", "Save As", select a location and enter it in the "File name (n)" box.

Batch file name. bat"

or"Batch file name. cmd"

Note that including quotation marks, the quotation marks here are half-width quotation marks, that is, quotation marks are typed without opening the input method.

Batch filename" is replaced with the file name you want, bat or cmd is the batch file format dropout.

2。Click "Start" in the bottom left corner, select "Run", and enter.

notepad

C: Enter, where C: is replaced with the path and file name you want, when Notepad is opened, it will prompt you that the file does not exist, whether to create or not, select Yes.

Then enter the batch and save.

3。Open ms-dos(start, run, cmdenter; or start, all programs, attachments, command prompt), hit the command at the command prompt.

copyconc:\

After entering, directly enter the batch**, when the input is finished, press Ctrl+Z (first hold down the Ctrl key and then press the Z key to release), after entering, the file is created and has been filled**.

4。This method requires the untick before "Hide extensions of known file types" under the "View" tab in the "Folder Options" (in the Explorer "Files" menu). Right-click directly where you need it, create a new text document.

Then open this document and enter it to save, exit, and then directly change this file to the file name you need. cmd or. bat

1. Type touch and add the file name to the terminal, and a file is created.

2. Use the ls command to view the file you just created.

3. Then you can feel free to use this file.

Creating a new folder in Linux is actually very simple, but it is very different from right-clicking in Windows.

1. Use the touch command: touch filename.

2. Use the command: vi filename directly, and there will be this file after saving.

If you want a document, you can do it directly, as you have a document.

File aa can be used vi aa [note: must be in the directory where aa is located] if there is no document and you want to, you can directly vi aa [name you can name whatever you want] can also create a document touch aa and then vi aa has three modes: 1 command line mode 2 end line mode 3 input mode, press esc to enter the command line mode, which is also the default mode of the system, and the input mode can be entered by pressing o i a Exit to enter the last line and command line mode, and the last line mode can be pressed Ctrl+; Its main function is that the exiter can also save the exit document Q![Force exit without saving] Q [Exit without saving] wq [You can also add one after exiting and saving!

There are a lot of commands in input mode and command line mode, if you want to know which ones you can say in and I say such as copy (yy), paste (p), delete (d) and so on.

How to create a new folder in linux with commands.

First of all, touch can be used to create binary files, and the usage is very simple. Usage: touch + file name, there must be a space between touch and file name.

In the figure, let's use the command we shared earlier to check how many files are in the directory and the names of the files.

For example, if I want to create a binary file with the file name abc, then the formula should be written as touch abc in linux, and the specific operation is shown in the figure.

After the creation is completed, use the ls command to view the file we created, and you can see that the abc file pointed by the red arrow in the figure is the newly created file.

In saying a command mkdir to create a folder, mkdir can create a folder, the usage is very simple, usage: mkdir + folder name, mkdir and the file name must have a space between it. In the figure, let's use the command we shared earlier to check how many files are in the directory and the names of the files.

For example, if I want to create a folder with the file name one, then in linux the formula should be written as mkdir one, and the specific operation is shown in the figure.

After the creation is completed, use the ls -l command to check the properties of the file, and you can see that the folder pointed by the red arrow in the figure is the newly created.

Linux two major tools vi, emacs. You can learn it yourself, but it's hard to get started.

For a similar experience to Notepad, you can use Nano

To create a MySQL database on the CLI, log in to the MySQL database system and perform the following steps:

Under the Windows operating system, Start - Run, Open"Run"dialog box, enter cmd, click "OK" to enter the DOS window, and enter the command to log in to the MySQL database.

mysql -h -u root -p

Parameter meaning: mysql is a command to log in to the database, -h followed by the IP address of the server, because the mysql server in this example is installed locally, the IP address is; -u is followed by the username, and in this example the root user is logged in; -p followed by the login password.

Enter the above command, press Enter, and then enter the login password, the default password is root, press Enter, and you can use SQL statements in DOS after successfully logging in to the MySQL database"create database"The database has been created.

mysql>create database The name of the new database to be created;

mydb1 in the figure is the newly created database.

Database creation statement: "mysql> use database name; mysql> create table table name (field name varchar(20), field name char(1))".

1. Create database database name;

2. grant select,insert,update,delete,create,drop,alter on database name. * to database name@localhost identified by'Password';

3、 set password for

The name of the database'@'localhost' = old_password('Password');

Run three commands in turn to create the database. Note: The Chinese "password" and "database" are set by the user himself.

The method and detailed operation steps are as follows:

1. The first step is to create two BAT files for testing, see the figure below, go to the steps below.

2. In the second step, after performing the above operations, write a self-writing program to test1, see the figure below, and go to the steps below.

3. In the third step, after performing the above operations, write a program to test2, see the figure below, and go to the steps below.

4. Step 4, after performing the above operations, double-click to execute, and then view the running effect, see the figure below, go to the steps below.

5. In the fifth step, after performing the above operations, call, key value2, key value3, see the figure below, go to the steps below.

6. In the sixth step, after performing the above operations, run it again to see if the result is correct, see the figure below. In this way, the problem is solved.

1. Create two BAT files for testing, as shown in the following figure.

2. Write the program to test1.

3. Write a program to test2.

4. Double-click to execute and see the running effect.

5、call %key_value1%,%key_value2%,%key_value3%。

6. Execute it again to see if the running result is correct.

Notes:c: The batch file in the root directory of the disk is an automatic batch file, which will automatically run the file every time the system starts, that is, you can put the commands that you want to run every time the system starts into the file, such as setting the search path, calling in the mouse driver and disk cache, setting the system environment variables, etc.

The description is too simple, and the parameters will be interpreted by cmd as different forms according to different situations, it can be a file path, it can be a number, it can be a string, just use the description of "two parameters", it can't give you an accurate answer to judge whether it is a or b, and it's even more confusing, what do your a and b mean, simply represent"a"with"b"These two characters are spoken when the user's first input is with"a"This character is the same, and the user's second input is with"b"This character is the same.

Execute the following commands, do you need to make such a string comparison judgment?

Or is it going to mean something else, please be specific.

If you are only comparing strings, write as follows:

echo off

set /p args1="Enter the 1st one:"

set /p args2="Enter the second one:"

if "%args1%"=="a" if "%args2%"=="b" (

Command 1 to be executed

Command 2 to be executed

Command to be executed3

Command n to be executed

For example: begin

set p a1=Please enter the first argument and press enter:

set p a2=Please enter the second argument and press enter:

if "%a1%"=="1" (

if "%a2%"=="a"goto next)rem here is a command that you are going to do if you are going to enter something incorrect, rem can make it turn back to this before, let the re-type goto beginrem or go to the end of the **goto :eof:next

rem next command series.

Of course, if you wish, you can also enter both parameters at once.

However, the form you hypothetically put is not practical, so why do you need to enter two parameters before performing the next step, usually several parameters are set to execute different command steps or pass different input data to the batch for processing.