CS140M Fall 2014 Overview • Will learn to create batch files to automate a sequence of commands to accomplish various tasks. Intro to Batch Files • The use of batch file subcommands will be discussed and then used with batch commands. • How to halt the execution of a batch file will be explained. By Al Lake • Will write batch files using replaceable parameters. Fall 2014 LBCC • Learn how batch files can be used from the desktop. CS140M Fall 2014 CS140M Lake 2 Concepts of Batch and Concepts of Batch and Interactive Processing Interactive Processing Batch file: Batch file: • Must be an ASCII file • String together series of commands • Created with Edit, COPY CON, text editor, or executed sequentially with one command word processor which has “Save as text file” without human interaction or interruption option • Has .BAT or .CMD extension • Each line in batch file contains only one command Fall 2014 CS140M Lake 3 Fall 2014 CS140M Lake 4 ASCII Chart Concepts of Batch and Interactive Processing Why batch files are used: • Minimize keystrokes • Automate frequent/consistent procedures • Do not need to interact with computer while batch files are running Fall 2014 CS140M Lake 5 Fall 2014 CS140M Lake 6 Lake 1 CS140M Fall 2014 Concepts of Batch and Concepts of Batch and Interactive Interactive Processing Processing Batch processing: Interactive processing: • Automate frequent/consistent • Also called online or real time mode procedures • User interacts directly with computer • Batch files can be run at anytime • Information processed without delay • No user/computer interaction required Fall 2014 CS140M Lake 7 Fall 2014 CS140M Lake 8 How Batch Files Work How Batch Files Work •The operating system determines if a file is a data file or a program file by the file extension. •File extensions: – .BAT batch file – .DOC MS Word file – .XLS MS Excel file Fall 2014 CS140M Lake 9 Fall 2014 CS140M Lake 10 How Batch Files Work How Batch Files Work To locate file, operating system: If file not found, get error message: • Looks internally for command • Using Extension Priority Rules, “Filename is not recognized as an searches on default drive and directory internal or external command, • Searches search path as set in PATH operable program, or batch file.” statement following Priority Rules Fall 2014 CS140M Lake 11 Fall 2014 CS140M Lake 12 Lake 2 CS140M Fall 2014 How Batch Files Work Using an Editor to Write Batch Files • A batch file is a program. Word‐processing programs can create text files if they have a • Each line in a batch file must nondocument or text mode. contain only one command. Fall 2014 CS140M Lake 13 Fall 2014 CS140M Lake 14 Using an Editor to Write Batch Activity—Writing and Files Executing a Batch File KEY CONCEPTS: • Create batch files with any text editor or Notepad: word processor with ASCII output • Window’s text editor • Batch file extensions ‐ .BAT or .CMD • Execute the batch file the same ways as • Used to write batch files you do any command Fall 2014 CS140M Lake 15 Fall 2014 CS140M Lake 16 Writing and Executing a Batch Writing and Executing a Batch File to Save Keystrokes File to Save Keystrokes Batch files can save keystrokes. Sometimes easier to use COPY CON instead of EDIT to write simple batch file. Examples: DIR/AD Syntax: DIR/OS and DIR/O‐S COPY CON filename Fall 2014 CS140M Lake 17 Fall 2014 CS140M Lake 18 Lake 3 CS140M Fall 2014 Writing and Executing a Activity—Writing & Executing Batch File to Save Keystrokes a One‐Letter Batch File Drawbacks to using COPY CON: KEY CONCEPTS: • Cannot correct errors once • Pressing <F6> and <Enter> signals completion • <Ctrl> +Z same as pressing <F6> <Enter> is pressed • Displaying file with TYPE indicates it is ASCII file • Cannot correct errors in • Create one‐line batch files existing files • Directories have no size Fall 2014 CS140M Lake 19 Fall 2014 CS140M Lake 20 Activity ‐ Creating a Batch File to Alter Using Batch Files to Alter Your the Command Line Session Environment Command Line Environment Open command line session by: KEY CONCEPTS: • Created shortcut to open command line • Clicking icon on Start menu session on desktop • Clicking shortcut • Can decide what directory to be in • Can be altered to run in customized way • With /k parameter ‐ include batch file that is executed each time command line session opened • Value limited on floppy • Valuable on hard drive Fall 2014 CS140M Lake 21 Fall 2014 CS140M Lake 22 Creating Shortcuts for Creating Shortcuts for Batch Files on the Desktop Batch Files on the Desktop To run a batch file from Windows: Some things can be done with • Double‐click file name in shortcut that cannot do in the command line interface. Windows Explorer/My Computer • Click shortcut to execute batch • Create shortcut for file and place on desktop and click icon • Can change shortcut icon Fall 2014 CS140M Lake 23 Fall 2014 CS140M Lake 24 Lake 4 CS140M Fall 2014 Batch Files to Run Windows Activity—Creating a Programs Shortcut on the Desktop KEY CONCEPTS: •Where Windows system files • Clicking shortcut executes file reside will vary depending on • Can change icon so it is more installation of Windows XP distinctive Professional. Fall 2014 CS140M Lake 25 Fall 2014 CS140M Lake 26 Batch Files to Run Windows Activity—Creating a Batch Programs File to Run Notepad Windows “keeps notes” about itself in KEY CONCEPTS: system environment. • %SYSTEMROOT% (Environmental variable) o Windows knows where Windows files are located • Path stored in environmental variable and substitutes correct name %Path% o %% signs around name ‐ OS substitutes value for that variable. • Drive referred to in environment as • Opened Notepad without returning to %SystemDrive% desktop • Directory where system files are located •Used Notepad to create log file (case referred to as %SystemRoot% sensitive) •Created log file Fall 2014 CS140M Lake 27 Fall 2014 CS140M Lake 28 Activity—Creating a Batch File to Run Notepad Batch File Commands KEY CONCEPTS: • START command: o Can start a program in new window while still executing batch program in previous window o If title following command is in quotes, will give window that title Fall 2014 CS140M Lake 29 Fall 2014 CS140M Lake 30 Lake 5 CS140M Fall 2014 Batch File Commands The REM Command REM command (remarks) allows user to place comments in file that are displayed but not executed Fall 2014 CS140M Lake 31 Fall 2014 CS140M Lake 32 The REM Command Activity—Using REM KEY CONCEPTS: REM allows file to be documented: o Purpose of REM ‐ provide explanatory o Gives explanation of the purpose of a remarks about the batch file program o If line begins with REM ‐ explanatory text follows and no action taken o Can include name of batch file, last time it was updated, and author of o No more lines in batch file ‐OS returns to system level batch file Fall 2014 CS140M Lake 33 Fall 2014 CS140M Lake 34 The ECHO Command The ECHO Command ECHO ON command: ECHO OFF command: o Displays command and the o Minimizes screen clutter command’s output to the screen o User turns off display of command o Is the default value then only see command’s output Fall 2014 CS140M Lake 35 Fall 2014 CS140M Lake 36 Lake 6 CS140M Fall 2014 The ECHO Command Activity—Using ECHO KEY CONCEPTS: o ECHO ON ‐ see remarks and commands o ECHO OFF ‐ output displayed not actual commands o @ECHO OFF ‐ @ suppresses display of ECHO OFF o Purpose of batch files defeated if interaction required by user Fall 2014 CS140M Lake 37 Fall 2014 CS140M Lake 38 Activity—Using ECHO The CLS Command CLS command used to clear screen when it becomes full of no longer needed information. Fall 2014 CS140M Lake 39 Fall 2014 CS140M Lake 40 Activity ‐ Using CLS The PAUSE Command KEY CONCEPTS: PAUSE command instructs the o After ECHO turned off screen cleared batch file to stop executing until the user takes some action. Fall 2014 CS140M Lake 41 Fall 2014 CS140M Lake 42 Lake 7 CS140M Fall 2014 Activity—Using Pause Stopping a Batch File from Executing KEY CONCEPTS: To interrupt a batch file during o Batch file “paused” ‐ stopped execution: executing until a key is pressed ‐ action is taken o Press <Ctrl> + C o Press <Ctrl> + <Break> Fall 2014 CS140M Lake 43 Fall 2014 CS140M Lake 44 Stopping a Batch File Activity—Quitting a Batch from Executing File KEY CONCEPTS: o Results of Pressing <Ctrl> + C Return to system prompt o Because of speed of computer difficult to when batch file interrupted. ascertain how many lines of batch file read when <Ctrl> + C pressed Fall 2014 CS140M Lake 45 Fall 2014 CS140M Lake 46 Replaceable Parameters Replaceable Parameters in Batch Files in Batch Files Can use fixed or variable Example of fixed parameter: parameters with batch files. o DIR A: /W Examples of variable parameter: o TYPE THIS.FIL o TYPE TEST.TXT Fall 2014 CS140M Lake 47 Fall 2014 CS140M Lake 48 Lake 8 CS140M Fall 2014 Replaceable Parameters Replaceable Parameters in Batch Files in Batch Files Can parse batch commands: • Batch files can also use replaceable parameters. • Keying in additional information on command line • Replaceable parameters also called • Dividing computer language into dummy, substitute or positional parts that can be made useful to parameters. computer Fall 2014 CS140M Lake 49 Fall 2014 CS140M Lake 50 Replaceable Parameters Replaceable Parameters in Batch Files in Batch Files User supplies markers (place holders) to let batch file know The place holder used in batch that variable will be keyed in files is the percent sign (%), with batch file name. followed by a number (0‐9).