Batch Scripting | Batch Programming | Batch File | Batch Tutorial | Scripting Made Easy | Working with Batch Scripting

Prerequisites

- Computer programming knowledge.
- Windows command line commands basics.

What is Windows Command Prompt | Command Line | Command Shell | cmd | cmd.exe | Command Line Interpreter?

Command prompt is an executable windows application which is available on most of the operating systems. It supports a list of windows commands. Command line interface helps in performing windows operations like creating/deleting/renaming/copying/moving folders or files, open files or applications etc.

What is a batch file?

A batch file or a batch script or batch job is a file which contains the list or collection of commands which will execute sequentially from top to bottom in command window. In windows operating system a batch file stored with an extension *.bat.

Batch scripting advantages

- Run multiple processes at a time
- Perform repetitive tasks
- Back up files
- Easy to manage large processes
- Saves time by running collection of commands
- Can call one batch from another batch
- Supports the user inputs as an arguments
- Publishing applications
- Supports all the windows command line commands
- Can work with git commands (git installation required)

In this tutorial you will be introduced with the basic batch scripting commands.

Batch file commands

ECHO

@ECHO [ON/OFF] - sets the command-line settings. ON - Displays the executing commands on command window, OFF - won't displays the  commands on window.
ECHO [Text] - Print text to the screen)
ECHO. - Print an empty line to the screen
ECHO - Displays the current setting of the command-line

PAUSE

Stops the commands execution and wait for any key press.

REM

Adds comment in script file.

Example:
REM comment details will goes here

EXIT

Terminates execution and closes the command window.

Variables

Variable can be initialized with SET command.

Syntax: SET [/A] [variable-name]=value
/A - If the value needs to be numeric 

String variable: 

SET employeeName="Srinubabu Ravilla"
ECHO %employeeName%

The above script will print the "Srinubabu Ravilla" on screen. Variable can be accessed by surrounding with the %% as shown above.

String concatination: 

SET employeeFirstName=Srinubabu

SET employeeLastName=Ravilla
ECHO %employeeFirstName%+%employeeLastName%

The above script will print the "Srinubabu Ravilla" on screen by combining both first name and last name variables.

Numeric variables: 

SET /A employeeFixedPay=500000

SET /A employeeVariablePay=100000
ECHO Employee total salary: %employeeFixedPay% + %employeeVariablePay%

The above script prints the "Employee total salary:600000 " on screen.

Prompt user for input:

SET /p userInput=Enter employee name: 

ECHO User input: "%userInput%"

The above script prints the user entered input on screen.

Escape sequence

Most special characters can be escaped using the caret (^) below are the list of characters that can be escaped.

Example: 
ECHO Mobile number format ^<Country-Code^>^<10-digit-numeric-value^>

The above script will print "Mobile number format <Country-Code><10-digit-numeric-value>"

Directories

Get the current batch script execution directory:
An environment variable CD stores the current command directory
ECHO Current directory: %CD%

Windows commands can be utilize in the batch scripting. Below are the few examples.

Change from one directory to another:
cd /d c: 

 
Navigate to another directory by directory path:
SET folderPath=C:\Users - Manual path

CD %folderPath%  - With path from variable

 
Create a new folder:
md "NewFolder1234" - Create folder in current directory
md "c:\Users\sravilla\test123" - Create new folder in by path
md %directoryVariable% - Create directory from variable/user input 

 
Open Folder:
%SystemRoot%\explorer.exe %FolderPath%
%SystemRoot%\explorer.exe "C:\Users"

Start

Start command can be used to start the program
START C:\Users - Opens the directory
start notepad.exe - Opens notepad
START https://dotnetcookie.blogspot.com/ - Opens the URL in default browser
START mailto:srinubabu.ravilla@gmail.com - Creates a new email in mail application

Loops

Unlike other programming languages batch scripting supports only for loop. The definition of a loop is,  statements execution repeats until specified condition is satisfied.

Basic Syntax:
FOR %%variable_name IN list DO commands

list - List of any elements, separated by either spaces, comma's or semicolons.
command - Can be any internal or external command, batch file, list of commands.
%%variable_name - Variable declaration in loops is specified with %%variable_name instead of %variable_name%.

Looping through numbers

FOR %%x IN (1 2 3 4 5 6 3 2 1) DO Echo %%x

The above script prints all the numbers from starting to ending.

Looping through range of values 

Batch scripting supports numeric range looping. 

Syntax: FOR /L %%variable_name IN (LowerLimit, Increment, UpperLimit) Do some_code

/L - Specifies the loop  suppose to iterate through the range of values.

LowerLimit - The minimum numeric start value  

Increment - Numeric increment which adds to LowerLimit in each iteration 

UpperLimit - The maximum value in a range to limit with 

FOR /L %%Number_Variable IN (0, 2, 15) DO ECHO %%Number_Variable

The above script prints the range of values between 0 and 15 with the increment of 2 in each iteration.

Output: 0,2,4,6,8,10,12,14

Loop through files

Batch script supports looping through the files in current directory. File lookup (*.*) specified in the below command can support the wild card search like (*.jpg). 

for /r %%file_path in (*.*) do echo %%file_path  

Looping through directories/folders

Batch script supports looping through the directories (Includes sub directories) in current directory. Directory lookup ("*") specified in the below command can support the wild card search like (*.jpg). 

for %f in (.\*) do @echo %f                - Files in current directory

for /D %s in (.\*) do @echo %s         - Subdirs in current directory

for /R %f in (.\*) do @echo %f         - Files in current and all subdirectories

for /R /D %s in (.\*) do @echo %s    - subdirs in current and all subdirectories

So, this is all about the batch scripting. Please start with the basic commands and practice in you machine to get familiar understanding and effective learning.