Bat cmd Batch File Script Summary

1. Summary

(1). ". Bat": This is the suffix of Microsoft's first batch of processed files and can be run in almost all Windows operating systems.

(2). ". cmd": it is a command line script designed for Windows NT. It is designed for cmd.exe shell and does not have backward compatibility with command. com.

(3) what is currently known. CMD and. the difference in the BAT file is the change to the errorlevel variable: When the command extensions (command line extension) is in the Enabled state, even if it is. A successfully executed command in the CMD file can change the value of errorlevel. in the BAT file, the errorlevel variable is changed only when an error occurs.

2. @ echo off/echo on

(1). "Echo" is used to display information on the console.

(2). "Echo." is used to display an empty row. (Note: There is no space between the ECHO and the vertices in the lower right corner. If there is a space, the periods are displayed .)

(3). "echo off": After this command is used, other commands only display the command results, rather than the command itself.

(4). "echo on": This is the default value, indicating that all command results and command lines are displayed.

(5 ). "Echo": When Echo is executed without any parameters, the status of ECHO is displayed: "Echo is on" or "Echo is off ".

(6). "@": @ indicates that the command itself of the current line is not displayed. If only echo off is used, although the command after echo off is not displayed, only the command result is displayed, but echo off is indeed displayed, this is why @ echo off is used.

3. setlocal/endlocal

(1). SETLOCAL is used to control the visibility of variables in the batch files. It is a local variable that is often used in advanced languages. All variables between SETLOCAL and ENDLOCAL are local, so that the value of the variable is not changed by other script files. All variables that do not use this label are Global visible ), may be changed by other files. The example below demonstrates this point.

@echo　off setlocal　 set　version=1.0 echo　the　first　version　is　%version% endlocal echo　the　second　version　is　%version% ::The　follow　is　global　variable set　version=2.0 echo　the　third　version　is　%version%	Execute this file and output:   the　first　version　is　1.0 the　second　version　is the　third　version　is　2.0 The second version is a global variable but is not defined, so it is a null value. Execute again: the　first　version　is　1.0 the　second　version　is　2.0 the　third　version　is　2.0
@echo　off setlocal　 set　version=1.0 echo　the　first　version　is　%version% endlocal echo　the　second　version　is　%version% ::The　follow　is　global　variable set　version=5.0 echo　the　third　version　is　%version%	Run the second file:   the　first　version　is　1.0 the　second　version　is　2.0 the　third　version　is　5.0 Execute again: the　first　version　is　1.0 the　second　version　is　5.0 the　third　version　is　5.0

It can be seen that the scope of the variable is still very careful in the simple batch processing file, otherwise it can cause ever-changing results, so this script is very unstable. Therefore, the variable scope is very important.

(2). EnableDelayedExpansion. (See Baidu: http://baike.baidu.com/view/2923132.htm)

Code	Result
@echo　off setlocal set　var=test　&　echo　show　%var% endlocal	Show When % var % is parsed, CMD has not executed any statements, so the system does not know the variable, so it is considered that the variable is not defined, so it shows a null value.
@echo　off Setlocal　ENABLEDELAYEDEXPANSION set　var=test　&　echo　show　!var! endlocal	Show Test Variable latency extension is used! VaR !, In fact, this variable is not recognized during execution, but after this statement is executed, the return value is assigned. The Variable Delay extension is used for post-processing.
The for statement seems to have written many rows, which is actually considered as a statement. Therefore, if the variable delay extension is not used, every row in the for statement only remembers what the system remembers. After Variable Delay extension is used, the entire statement is executed, and the value is assigned after "event processing" before being displayed on the console. The following example illustrates the problem.
@echo　off setlocal ::　count　to　5 set　_tst=0 FOR　/l　%%G　in　(1,1,5)　Do　(echo　[%_tst%]　&　set　/a　_tst+=1) echo　Total　=　%_tst%		[0] [0] [0] [0] [0] Total　=　5
@echo　off setlocal ::　count　to　5 set　_tst=0 FOR　/l　%%G　in　(1,1,5)　Do　(echo　[!_tst!]　&　set　/a　_tst+=1) echo　Total　=　!_tst!		[0] [1] [2] [3] [4] Total　=　5

In CMD, the system uses "^" as the escape character. After the variable delay extension ENABLEDELAYEDEXPANSION is used, the escape character ^ can always be used, instead of being limited to one command line. In this way, it is much easier to process characters in HTML and XML format. See the following example.

@ Echo off

The REM file creates world.txt to the local disk. The file content is Hello.

REM, that is, during the second operation, the escape character does not play a role.

SETLOCAL　
Set　_html=　Hello^>World.txt
Echo　%_html%
ENDLOCAL

@ Echo off

This file will output Hello> World.txt, which will take effect all the time.

SETLOCAL　EnableDelayedExpansion
Set　_html=　Hello^>World.txt
Echo　!_html!
ENDLOCAL
@echo　off

REM uses variable latency extension to process html statements.

SETLOCAL　EnableDelayedExpansion
Set　_html=html　format:　^<title^>Hello　world^</title^>
Echo　!_html!
ENDLOCAL

(3). DISABLEEXTENSIONS.

It is worth noting that the extension here is not the extension, but the extension function of the command. For example, the "/F" parameter is the command extension of the For loop.

The following statement can be executed only when command extension is used.

FOR/F "DELIMS =" % a IN (test. TXT) DO @ echo %

Otherwise, we need to output a file. We can only use Type test.txt. Command extension is enabled by default.

4. Set

(1). SET without any parameters: All system environment variables of the current user are displayed. (Set)

(2). SET with a variable name: Search and display the environment variable starting with this variable name. (Set PROCESSOR will display the variables starting with PROCESSOR)

(3). SET variable = string: assign a value to a variable.

(4). SET "": use an empty pair of double quotation marks to display a variable that is not displayed without parameters. Here I will show two strange variables.

= C: \ Users \ Lingli

= E: \ Powershell

You can use cd % = C: % To Go To The C: \ Users \ Lingli directory.

(5). SET "var =" (or SET var =): delete a variable.

(6). SET/A variable = expression: assign values to variables using Arithmetic Operators.

()-Combination

! ~ --Unary operator

*/%-Arithmetic Operator

+--Arithmetic Operator

<>-Logical offset

&-Bit and

^-Bitwise OR

|-Bit or

= * =/= % = + =--Value assignment

<=>>=

(7). Set/P variable = [prompt character]: prompt the user to enter and assign the input value to variable. The prompt character can be blank. Sometimes choice can be used instead of set/P.

@echo　off
setlocal
set　/p　version=Please　enter　the　QQ　version:
echo　you　will　install　QQ　%version%
endlocal

(8). Useful environment variables.

% Cd %-current path name.

% Date %-current date.

% Time %-current time.

% Random %-displays a random number between 0 and 32767. You can see that cmd can also obtain random numbers.

5. Choice

(1). Detailed Syntax:

Choice [/C choices] [/n] [/CS] [/T timeout/d choice] [/M text] This command provides a user selection list and uses the errorlevel parameter to return the sequence number of the selected item. For 1, for 2, and so on, if you press Ctrl + C to exit without selecting, 0 is returned.

/C choices   /N /CS /T timeout /D choice /M text

Use letters to list the provided options. The default value is "YN", that is, and no.   Hide the selection list. If this option is used, the following is clearly written in the prompt text. It is not recommended. Enable case sensitivity. The default value is case insensitive. Select timeout settings. Default options after timeout. Prompt characters. It is best to clarify the question to be selected.

(2). Example:

@ Echo off
Setlocal
Choice/c abc/M "select Login User: A-administrator, B domain user, C registered user"
If % errorlevel % = 1 Goto: Admin
If % errorlevel % = 2 Goto: domain
If % errorlevel % = 3 Goto: Local
Goto exit
　
: Admin
Echo welcome Administrator
Goto exit
　
: Domain
Echo welcome Domain Users
Goto exit
　
: Local
Echo welcome to registered users
Goto Exit
　
: Exit
Endlocal

6. REM and arguments.

(1). Rem [comment]: Annotation of the batch file. You can use ":" To replace REM.

(2). parameters.

% 0 corresponds to the file name, and the others correspond to one parameter value. 255 parameters are supported.

Test. cmd	1	2	3	...	N	...	255
% 0	% 1	% 2	% 3	...	% N	...	% 255

(3). Extension of file name parameters.

When using a file name as a parameter, you can use the following file name extension. In the following example, % 1 is extended. In fact, all parameters can be extended similarly.

% ~ F1-extension % 1 is the full name with path.
% ~ D1-only display the disk name.
% ~ P1-only the file path is displayed.
% ~ N1-only display the file name, excluding the suffix and path.
% ~ X1-only show the suffix.
% ~ S1-change to a short file name, which will contain "~" Symbol.
% ~ 1-if the file name contains spaces, double quotation marks are added to the file name. This function removes double quotation marks.
% ~ A1-display file attributes.
% ~ T1-display the file modification time.
% ~ Z1-displays the file size.
　

The above extensions can be combined:

% ~ Dp1-extended % 1 is the disk name and path name.

% ~ Nx2-extension % 2 is the file name and file suffix.

::Test.bat
::Example:　test.bat　test.bat
@echo　off
setlocal
set　fn=%~f1
echo　%fn%
endlocal

7. IF statement

(1). Detailed Syntax:

File　syntax　　　
IF　[NOT]　EXIST　filename　command　
IF　[NOT]　EXIST　filename　(command)　ELSE　(command)
　
String　syntax　　　
IF　[/I]　[NOT]　item1==item2　command　
IF　[/I]　item1　compare-op　item2　command
IF　[/I]　item1　compare-op　item2　(command)　ELSE　(command)
　
Error　Check　Syntax
IF　[NOT]　DEFINED　variable　command
IF　[NOT]　ERRORLEVEL　number　command　
IF　CMDEXTVERSION　number　command

Key

/I: The file name is case-insensitive when compared.

Compare-op: logical comparison

EQU: equal

NEQ: not equal is not equal

LSS: less

LEQ: less than or equal is less than or equal

GTR: greater

GEQ: greater than or equal is greater than or equal

(2). Example (we can see that the If statement is also a statement)

If exist filename (del filename) ELSE (echo The file was not found .)

IF　EXIST　filename　(
del　filename
)　ELSE　(　
echo　The　file　was　not　found.
)

8. For Loop

(1). Detailed Syntax:

FOR-Files
FOR　%%parameter　IN　(set)　DO　command　
　
FOR-Files-Rooted　at　Path　　　
FOR　/R　[[drive:]path]　%%parameter　IN　(set)　DO　command　
　
FOR-Folders
FOR　/D　%%parameter　IN　(folder_set)　DO　command　
　
FOR-List　of　numbers　　　
FOR　/L　%%parameter　IN　(start,step,end)　DO　command　
　
FOR-File　contents　　　
FOR　/F　["options"]　%%parameter　IN　(filenameset)　DO　command　
FOR　/F　["options"]　%%parameter　IN　("Text　string　to　process")　DO　command
　
FOR-Command　Results　
　　　　　　　FOR　/F　["options"]　%%parameter　IN　('command　to　process')　DO　command

Eol = c-line first annotator. If this annotator exists, this line is not processed.

Skip = n-the first n rows are skipped and not processed

Delims = xxx-delimiter set. The default Delimiter is space and Tab.

Tokens = x, y, m-n-which is used for cyclic operations.

Usebackq-when the file name contains spaces that require double quotation marks, usebackq is used to process the content in double quotation marks as a file; otherwise, it is processed as a string.

Note:

In the batch file, % parameter is used for parameters. When you get the command line, % parameter is a percent difference. Variable names are case sensitive, so % g and G are different.

(Set) indicates a collection of files, one or more files, you can also use wildcards for file names.

(2). Example:

@echo　off
setlocal
for　%%G　in　(*.bat　*.txt)　do　echo　%%G
endlocal

9.net.

(1). Management service: Net start, stop, pause, and continue [service].

(2) connect to a shared file: Net use.

Net use [disk name:] \ shared name [\ subdirectory name] [Password] [/USER: [Domain Name \] USER name]

Net use disk name:]:/delete

(3). Net share: displays all local shares, including hidden shares.

(4). Net share ShareName: displays the shared information.

(5) create a local SHARE: net share sharename = drive: path/REMARK: "text" [/CACHE: Manual | Automatic | No]

(6) modify the user quantity limit and Mark.

Net share sharename/USERS: number/REMARK: "text"

NET Share sharename/unlimited/remark: "text"

(7). Delete share: net share {sharename | devicename | drive: path}/delete

(8). Net view \ computer name: lists all sharing of remote machines.

(9). Net localgroup: add an account to a local group. For example, add an account to the Administrator group: Net localgroup administrators domainname \ Username/Add

(10). Rename the machine: netdomrenamecomputer original machine name/newname: Modified machine name/userd: User/passwordd: Password

(11). Add domain: Net Dom join computer name/domain: domain name/userd: domain administrator account/passwordd: domain administrator password