First knowledge of batch processing

The batch (Batch), Also known as batch scripts . seeing the name of a thing one thinks of its function , Batch processing is batch processing of an object , It is generally considered as a simplified scripting language , It is applied to DOS and Windows In the system . The extension of the batch is bat. There are two common types of batch processing ：DOS Batch processing and PS The batch . The following and subsequent introductions are mainly based on DOS Batch based .

The default storage format of batch files is ANSI, That is to use Windows System default encoding format . But we cannot directly create batch files , It is usually created by creating a text file and then changing the extension , Therefore, you need to manually change the encoding format of the file to ANSI Format , In this way, we can prevent Chinese from being garbled .

Interpreter

• Batch processing is case insensitive .
• By default, the batch interpreter reads a line of code , Then explain one line execution
• If the batch interpreter reads parentheses "(“, Think you know the next corresponding ”)", For the end . This method allows the batch interpreter to interpret and execute multiple instructions at one time （ stay if Especially in the sentence ）
• CTRL+C You can exit the currently executing batch .

grammar

echo

echo Instructions are the simplest and most common instructions in batch processing . It is equivalent to printing in other languages , Such as Python Of "print".echo You can output the information behind him on the terminal . Pay attention to the output information and echo There needs to be a space between .

echo Hello,World！

Close back display

When we create a batch script and write it, save and run the above instructions , Will find , Every command we write will be displayed on the terminal , Once the script is complex, it will look very ugly , Can we make it not show what commands we wrote ？ The answer, of course, is yes . We just need to add a @ Can be realized .

@echo Hello,World!

The problem is coming again , If there are more orders , Isn't it necessary to add one for each @, Is there a more convenient way ？ Of course. ！
echo off Indicates that echo function is turned off , You can place this command at the top of the script , thus , The echo of the commands written below will be turned off

@echo off
echo Hello,World!
echo Hello,batch!

When echo is turned on @echo on

Output blank lines （ Line break ）

In batch ",“、”.“、”:" Wait can follow closely echo Later, it plays the role of outputting blank lines . Note that there must be no spaces , Otherwise it will be output to the screen as information . It can also be used " / ] + \ These symbols replace .

Answer the questions in the order

You can use the pipe command , Use the previous results as input for the following . for example ：

@echo off
rd /s c:\abc
pause

In the above script , After execution , Will be displayed ：c:\abc, Are you sure (Y/N)?
Because here abc Is a folder that is not empty , So use rd Command to delete , Will ask you Y or N, At this time, you usually need to enter manually . We can modify the script and let the system automatically input Y Confirm ：

@echo off
echo Y|rd /s c:\abc
pause

Create documents or add document contents

@echo off
echo 123>myfile.txt
pause

The above command can create a file named myfile.txt The file of , The content of the document is 123, To continue adding content, you can use ：

@echo off
echo 456>>myfile.txt

If you want to create an empty file , Then you can use the command of outputting blank lines ：

@echo off
echo. >myfile.txt