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Editor to share with you how to use the Set command in batch processing, I believe most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

Set, E translates to mean "setting", which is equivalent to "order" in mathematics.

For example: set Xerox 5, which means Ling Xuan 5.

Grammatical form:

SET [variable= [string]]

SET / P variable= [promptString]

SET / An expression

1. SET [variable= [string]]

Example 1:

@ echo off

Set

Pause

Display the values of all variables

Example 2:

@ echo off

Set var=, I'm worth it.

Echo var%

Pause

Look at set var= I am the value, this is how BAT sets variables directly in the batch!

Set is the command var is the variable name = sign to the right "I am the value" is the value of the variable

To reference this variable in the batch, expand the var variable name with two% (percent sign), such as% var%

2. SET / P variable= [promptString]

Sometimes we need to provide an interactive interface for the user to enter the value of the variable, and then we will do the corresponding operation according to this value. Now I will talk about the syntax of the SET, just add a "/ P" parameter!

Example 1:

@ echo off

Set / p var= Please enter your name:

Echo your name is:% var%

Pause

Set / p is the command syntax var is the variable name = sign to the right of the "Please enter the value of the variable:", this is a prompt, not a change

It's worth it!

After running, we type robin directly after the prompt, and the line "your name is: robin" will be displayed.

3. SET / An expression

The / A command line switch specifies that the string to the right of the equal sign is the evaluated numeric expression.

The expression is simple to parse and supports the following operations in decreasing priority order:

()-grouping

! ~-- unary operator

* /%-arithmetic operator

+-arithmetic operator

>-logical shift

&-bitwise "and"

^-bitwise "different"

|-Bitwise "OR"

= * = /% = + =-= & = ^ = | =-assignment

,-expression delimiter

The / A parameter of set allows SET to support mathematical symbols for addition and subtraction and other mathematical operations!

Now let's give examples of the use of these mathematical symbols:

See the example here, please run the copy command directly under CMD, do not need to save as BAT!

Set / a var=1 + 1

Set / a syntax, var variable name 1 + 1 mathematical formula

After the copy is run, a 2 is displayed directly, or after running, we type echo% var%, is also 2, which is

A simple addition operation!

The code is as follows:

What is the result of set / a var=2-1? Echo% var%. if you can't see the result.

Set / a var=2 * 2 multiplication

Set / a var=2 / 2 division operation

Set / a var= (1: 1) + (1: 1) the result equals 4. Can you read it?

Example 1:

The code is as follows:

@ echo off

Set / an axiom 1, 2, 2, 1, 3, 3, 1

Echo a% b% c%

Example 2:

The code is as follows:

@ echo off

Set aura 100

Set bread1000

Set / a c=a+b

Echo the result is:% c%

Pause

Sometimes we need to add and subtract directly from the original variable to use this syntax.

A syntax such as set / a var+=1 corresponds to the original syntax set / a var =% var% + 1

It's all the same result, and we're doing mathematical operations on the values of the original variables, but it's a little easier to write this way.

Here's another one:

Set / a var*=2

Everything else is used in this way, as long as there is this grammar in the help!

In addition, some use logic or remainder operators, and these symbols will report errors according to the above method of use.

For example, if we type set / a var=1 & 1 "and operation" in CMD, it will not display as 1, but will report an error.

Why? For such "logical or remainder operators", we need to enclose them in double quotation marks. Look at the example.

The code is as follows:

Set / a var= 1 "&" 1 so that the result is displayed, other logic or remainder operator usage

Set / a var= 1 "^" 1 different operation

Set / a var= 1 "%" 1 modular operation

Set / a var= 2 "" 2 bit right shift

Example 3:

The code is as follows:

@ echo off

Set aura 100

Set bread1000

Set / a c=a+b

The character ">" of set / a c = c "" is a special character and will be treated as an orientator by the system, so there will be an error, so what if you do set such a variable str with a value of "ok >"? There are two solutions: escape the special character by adding a "^" before the special character, such as: set str= ok ^ > (this method is rarely used because it does not have much application value)

A common solution is to enclose the entire expression in quotation marks after the set, such as: set "str= >"

3. Numerical calculation of set with parameters / a

The / A parameter of set allows SET to support mathematical symbols for addition and subtraction and other mathematical operations! Supported mathematical operations include (decreasing priority):

()-grouping

! ~-- unary operator

* /%-arithmetic operator

+-arithmetic operator

>-logical shift

&-bitwise "and"

^-bitwise "different"

|-Bitwise "OR"

= * /% = + =-- assignment

& = ^ = | =

,-expression delimiter

Usage example: set / a num=2*10, so that the value of the variable num will be: 20

The code is as follows:

What is the result of set / a var=2-1? Echo% var%. if you can't see the result.

Set / a var=2 * 2 multiplication

Set / a var=2 / 2 division operation

Set / a var= (1: 1) + (1: 1) the result equals 4. Can you read it?

Set / an axiom 1, 1, 2, 1, 1, 2, 2, 1, 3, 3, 1, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 1, 4, 1, 4, 4, 4, 4, 4, 4, 4, 4, 1, 4, 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 1, 4, 1, 4, 1, 4, 1, 4, 4, 4, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4, 4,

Echo% a% b% c% after looking at the results, you will find that other mathematical operations are also effective! this is the "Dou"

It works!

Sometimes we need to add and subtract directly from the original variable to use this syntax.

A syntax such as set / a var+=1 corresponds to the original syntax set / a var =% var% + 1

It's all the same result.

For "logical or remainder operators", we need to enclose them in double quotation marks. See the example.

The code is as follows:

Set / a var= 1 "&" 1 so that the result is displayed, other logic or remainder operator usage

Set / a var= 1 "+" 1 different operation

Set / a var= 1 "%" 1 modular operation

Set / a var= 2 "" 2 "does not quite remember the name in mathematics.

These symbols can also be used in simple ways such as & = ^ =.

Set / a var "& =" 1 equals set / a var =% var% "&" 1 pay attention to quotation marks

4. Set with parameter / p waits for user input

Windows 2000 and windows do not have the command choice. The function of waiting for user input of choice is realized through set / p.

The demonstration is as follows:

The code is as follows:

@ echo off

Set / p str= Please enter the characters you want to enter:

Echo the string you entered is:% str%

Pause > nul

Special Application of set / p (set / p=nul)

Note: a sentence for / l% an in (1150) do ver > nul is used in the code, which aims to use for loop to run a command to achieve the purpose of delay.

5. Use set to intercept characters and save the following code for test.bat to run and view.

The code is as follows:

@ echo off&color 1f&rem num=15 nums=30

Mode con: cols=80 lines=35

Set "var=1234567890"

Set "num="

Set "nums="

Discard the first screen of rem

Discard the first screen of cls&echo

Echo\ & echo% num% var=%var%&echo\

For / l% I in (1 1 3) do call: dan% I

Echo\

For / l% I in (0 11) do call: yi% I

Echo\

For / l% I in (0 1 2) do call: _ yi% I

The number after the echo ~ tilde: a positive number indicates the leading position of the discarded variable

Echo, the positive number after the comma indicates the first few digits after the discarding of the variable

Echo, followed by a negative number to discard the last few digits of the variable

Echo\ & echo\ & pause&color 1e

Rem second screen fetch

Cls&echo second screen fetch

Echo\ & echo% num% var=%var%&echo\

For / l% I in (- 1-1-3) do call: dan% I

Echo\

For / l% I in (- 4-1-6) do call: er% I

Echo\

Call: _ er-8

The echo ~ tilde is followed directly by a negative number to indicate the last few digits of the variable.

Echo, the positive number after the comma indicates the first few digits after the discarding of the variable

Echo, followed by a negative number to discard the last few digits of the variable

Echo\ & echo\ & pause&color 1f

Rem third screen replacement deletion

Cls&echo third screen replacement deletion

Set "var=abc:\ 123\ ef:g\ 123\ 456" hij "789" klm\ "

Echo\ & echo% num%var=%var%

Echo\

Call: san

The left side of the echo = sign is the character to be replaced, and the right side is the character to be replaced

The character to be replaced to the left of the echo = sign is preceded by a * sign, which represents the character that appears for the first time and all the characters that precede it

Echo\

Echo = finished demonstration = press any key to exit =

Pause > nul

Exit

: dan

Set shu=%1

If% shu% lss 0 (set aa= fetch & set ji= Last) else set aa= discard & before set ji=

If "% shu:~0,1%" = "-" set shu=%shu:~1%

Set str1=%%var:~%1%%%num%

Ji%%shu% bit nums% of set str2=%aa%var

Call set str3=%%var:~%1%%%num%

Call echo str1:~0,15%% str2:~0,30%% str3:~0,15%%

Goto: eof

: yi

Set shu=%1

If% shu% lss 0 (set aa= fetch & set ji= Last) else set aa= discard & before set ji=

For / l% I in (1 1 3) do (

Set str1=%%var:~%1,%%i%%%num%

Take% I bit% nums% after the% ji% shu% bit of set str2=%aa%var

Call set str3=%%var:~%1,%%i%%%num%

Call echo str1:~0,15%% str2:~0,26%% str3:~0,15%%

If% iTunes 3 echo\

)

Goto: eof

: _ yi

For / l% I in (- 1-1-3) do (

Set str1=%%var:~%1,%%i%%%num%

Set str2= discards first 1 bit and I bit nums% of var

Call set str3=%%var:~%1,%%i%%%num%

Call echo str1:~0,15%% str2:~0,28%% str3:~0,15%%

If% iTunes 3 echo\

)

Goto: eof

: er

Set sss=%1

Set sss=%sss:~1%

For / l% I in (1 1 3) do (

Set str1=%%var:~%1,%%i%%%num%

Set str2= starts with the reciprocal% SSS% bit of var to take%% I bit% nums%

Call set str3=%%var:~%1,%%i%%%num%

Call echo str1:~0,15%% str2:~0,24%% str3:~0,15%%

If% iTunes 3 echo\

)

Goto: eof

: _ er

Set sss=%1

Set sss=%sss:~1%

For / l% I in (- 1-1-3) do (

Set str1=%%var:~%1,%%i%%%num%

Set str2= starts with the reciprocal% SSS% bit of var and discards the last%% I bit% nums%

Call set str3=%%var:~%1,%%i%%%num%

Call echo str1:~0,15%% str2:~0,20%% str3:~0,15%%

If% iTunes 3 echo\

)

Goto: eof

: san

Set str1=%%var: "=%% num%

Set str2= deletes all ^ "sign num% in var

Set str3=%var: "=% nums%

Call echo str1:~0,13%% str2:~0,23%% str3:~0,30%%

Set str1=%%var:\ =%% num%

Set str2= deletes all\ number% num% in var

Set str3=%var:\ =% nums%

Call echo str1:~0,13%% str2:~0,23%% str3:~0,30%%

Set str1=%%var::=%%%num%

Set str2= deletes all: number% num% in var

Set str3=%var::=%%nums%

Call echo str1:~0,13%% str2:~0,23%% str3:~0,30%%

Echo\

Set str1=%%var: "= good%% num%

Set str2= replaces all ^ "signs in var with the good word% num%

Set str3=%var: "= good% nums%

Call echo str1:~0,12%% str2:~0,20%% str3:~0,30%%

Set str1=%%var:\ = good%% num%

Set str2= replaces all the\ symbols in var with the good word% num%

Set str3=%var:\ = good% nums%

Call echo str1:~0,12%% str2:~0,20%% str3:~0,30%%

Set str1=%%var::= good% num%

Set str2= replaces all the: symbols in var with the good word% num%

Set str3=%var::= good% nums%

Call echo str1:~0,12%% str2:~0,20%% str3:~0,30%%

Echo\

Set str1=%%var:* "=% num%

Set str3=%var:* "=% nums%

Echo deletes the first occurrence of the ^ "sign in var and all characters preceding it.

Call echo str1:~0,15%% str3:~0,30%%

Echo.

Set str1=%%var:*\ =%% num%

Set str3=%var:*\ =% nums%

Echo deletes the first occurrence of the\ sign in var and all characters preceding it.

Call echo str1:~0,15%% str3:~0,30%%

Echo.

Set str1=%%var:*:=%%%num%

Set str3=%var:*:=%%nums%

Echo deletes the first occurrence of the: sign and all the characters before it in var

Call echo str1:~0,15%% str3:~0,30%%

Echo\

Set str1=%%var:* "= ppp%%%num%

Set str3=%var:* "= ppp%%nums%

Echo replaces the first occurrence of the ^ "sign in var and all the characters before it as ppp.

Call echo str1:~0,15%% str3:~0,30%%

Echo.

Set str1=%%var:*\ = ppp%%%num%

Set str3=%var:*\ = ppp%%nums%

Echo replaces the first occurrence of the\ sign in var and all its preceding characters as ppp.

Call echo str1:~0,15%% str3:~0,30%%

Echo.

Set str1=%%var:*:=ppp%%%num%

Set str3=%var:*:=ppp%%nums%

Echo replaces the first occurrence of the: sign in var and all the characters before it are ppp

Call echo str1:~0,15%% str3:~0,30%%

Echo\

Goto: eof

The above is all the contents of this article entitled "how to use Set commands in batch processing". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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