Using the window shell

8/7/2019 Using the window shell

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Using the Windows shell


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Useful commands

command/? get help on a command

cd /?

clear clears screen

md

make directory

copy

cd cd .. cd /

Change dir

change to parent dir

u:

change partition

help

list commands


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Windows shell scripting


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The shell reads,parses and executes the line

I write a batch file and run it

executes command and displays result

The shell displays the line it readsfrom the batch file

ANNOYING

The shell displays allthe commands itsabout to execute

ANNOYING

The shell displays allthe commands itsabout to execute


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@Echo off at the start of your script stops+ The @ stops Echo Off being displayed+ Echo off stops

+ the shell displaying REM statements+ the shell displaying the commands its about to execute

nice


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Your own Environment Variables

Use the setcommand to assign

(string) values tovariables

Use /a switch to

assign result of mathoperation to variable

Extract value fromvariable using

%var_name%


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Using command line arguments

%1 is first

arg %2 is the

second arg notice you

only use one% in thiscase


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Limiting scope of variable

use

SetlocalandEndLocal


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Program Control

Normally, all commands in the batch file will be executedin the order in which they appear in the file.

This is called a sequence.

Sometimes, there are circumstances in which you wouldlike to carry out commands in a different order or carry

out a single command repeatedly. echo off

REM print Paul all over the screen

:startecho Paulgoto startREM end of program

label


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Command Redirection

If you run the command Echo Fred was here

the screen displays the text Fred was here.

Redirect a command's output to a file with redirection symbols. > (overwrite) and >> (append)

Echo Fred was here > C:\fredreport.txt

Creates (or overwrites) fredreport.txt with Fred was here

Echo Barney was here >> C:\fredreport.txt

Creates (or appends) fredreport.txt with Barney was here


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IF

Reference

http://www.ss64.com/nt/index.htmlhttp://www.ss64.com/nt/index.html


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Some MathsUsing SET and IF

If logical_condition do_this

Logical conditions

EQU (equal to)

NEQ (not equal to)

LSS (less than)

LEQ (less than or equal to)

GTR (greater than)

GEQ (greater than or equalto)


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Execute code if a condition doesnt

exist


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Readability

You can improve the readability of a batch

script by writing a complex IF...ELSEcommand over several lines usingbrackets e.g.

IF EXIST filename (del filename)

ELSE (echo The file was not found.)


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Simple looping


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Combining commands

Dir /ad C:\ | Find /i "winnt" lists directories (only) and send results to Find which

will perform a case insensitive search for the stringwinnt in the file

The | is a pipeand it sends output from first commandto second

Echo Fred & Echo Wilma & Echo Barney & combines commands

Command A && Command B Do command B if command A is successful

Command A || Command B Bo command B is A is unsuccessful


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FOR...

http://www.ss64.com/nt/index.html


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Documents

Using the window shell