Introduction to ScriptingAE 6382
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What is a scripting
Scripting is the process of programming using a scripting
language A scripting language, like C, Fortran, and Java, has
expressions, conditional statements, and loop statements. Unlike C,
Fortran, and Java a scripting language has
Loose typing Interpreted rather than compiled Usually as some
higher level abstractions or built-in functionality
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Scripting Features
Scripting languages are generally interpreted rather than
compiled This results in slower execution times compared to a
compiled language
C and Fortran are generally fastest Java is compiled to bytecode
that runs on a virtual machine and is slower The implementation of
each individual interpreter varies greatly
Perl, Python, and Ruby are compiled at runtime into an internal
format that increases performance Shell scripts and MATLAB
re-evaluate each statement every time
Development cycle is shortened edit/run
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Scripting Features
Scripting languages do not, in general, use strong typing of
variables
A variable may during the course of execution contain strings,
integers, and objects
Scripting languages frequently build into the basic language
higher order abstractions
Text processing Regular expressions System interface
mechanisms
Most scripting interpreters can be embeddedt into other programs
to provide scripting capability within that program
Microsoft Office uses Visual Basic for ApplicationsAE6382
Scripting Languages
Simple command/shell scripting, level 1, is the simplest form of
scripting Intended to provide a batch execution capability
Unix/Linux
bash, ksh (Korn shell), sh (Bourne shell) csh (C shell), tsch
These shells can work interactively or in script mode Have basic
programming constructs (if, loops, ) cmd/command have no
programming constructs Windows PowerShell (4Q2006) will have
extensive scripting based on C# language
Windows
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Scripting Languages
Limited scripting languages, level 2, have more sophisticated
language structure but are limited in their native
functionality
No native file I/O capability for example Available on
Unix/Linux and Windows C based syntax Used almost exclusively as
the client-side scripting language in the various web browsers Can
be used as a system scripting language in Windows via the Windows
Scripting Host Not generally used in Unix/Linux for general purpose
scripting
JavaScript / Jscript / ECMAScript
SpiderMonkey is C based JS interpreter Rhino is Java based JS
interpreterAE6382
Scripting Languages
VBScript
Available only on Windows, based on Visual Basic for
Applications (VBA) Can be used as the client-side scripting
language in Internet Explorer Most often used with Windows Active
Server Pages (ASP) for IIS based web sites Can be used as a system
scripting language in Windows via the Windows Scripting Host
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Scripting Languages
Full scripting languages, level 3, have a sophisticated language
structure and extensive application support Perl Practical
Extraction and Reporting Language
A procedure based language with support for objects Extensive
text processing capabilities and regular expressions Extensible
using modules C based syntax with plethora of symbols Developed in
late 1980s An object oriented language with some procedure traits
Extensible A format based syntax Developed in early 1990sAE6382
Python (also Jython)
Scripting Languages
Ruby
An object oriented language Extensible C like syntax with
minimal symbols (no {} () ) Developed in early 1990s A procedural
language Extensible A stack evaluation syntax, similar to Lisp
(lots of []) Developed as an embeddable scripting language
Developed in late 1980s
TCL Tool Command Language
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Scripting Languages
Other niche scripting languages
BeanShell
Makes it possible to use Java as a scripting language C-like,
objects, cross-platform, has a Java version
REXX
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Perl
General purpose scripting language Practical Extraction and
Reporting Language Based on the Unix program awk in its early
incarnation Runs everywhere
On Unix/Linux it runs standalone using #! script file convention
On Windows it can run standalone or as an ActiveX scripting engine
Extensive text processing capabilities including built-in regular
expressions Can be easily extended, there is extensive support for
all types of system programming Has syntax to support object based
programming Most Unix system calls are built-in functions The
built-in system calls will do the right thing in WindowsAE6382
Pros
Perl
Cons
Can be difficult for beginners to learn Variable naming scheme
is initially confusing There is a high learning curve
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Perl
Has 3 classes of variables
$var @var %var
-
scalar (integer, real, string, ...) array of scalars, $var[0]
hash of scalars, $var{key}
Has local, lexical, and global scoping of variables Namespace
separation Objects and references are supported Has the same set of
operators as C plus some Lexical and global scoping of variables
Statements end with ; Comments are everything after # on a line
Functions sub name { ... }AE6382
Perl
Has the same set of operators as C plus some additional
Statements end with ; (semi-colon) Comments are everything after #
on a line The usual complement of conditional statements
if then else (also unless then else) for for each while sub name
() { }
The usual loop statements
Functions and methods are defined similarly
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Perl
Loop statementsfor ($i=0 ; $i < 10 ; $i++) { printf
i=%4d\n,$i; } while () { print; } @list = (0,5,8,12); foreach
$value (@list) { print Value=$value\n; } %hash =
(part1=>0,part3=>70,part2=>4); foreach $key (sort keys
%hash) { print Value=$hash{$key}\n; } foreach $value (0,5,8,12) {
print Value=$value\n; }
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Perl
Logical statementsif ($i == 1) { print i=$i\n; $i++; } unless
($i == 1) { print Error: i != 1\n; $i++; }
die Unable to open file if !open(IN,filename); if ($i == 1) {
print Group 1\n; } else { print Unknown group\n; } if ($i == 1) {
print Group 1\n; } elsif ($i == 2) { print Group 2\n; } elsif ($i
== 3) { print Group 3\n; } else { print Unknown group\n; }
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Perl
Native Regular Expression Support
while () { next if m/.*error.*/; print; } foreach $line (@lines)
{ next if $line =~ m/^#/; @values = ($line =~
m/.+a=([0-9]+).+c=([0-9]+)/); print $values[0] $values[1]\n; }
@lines contains (an array of strings): # a b c a=10 b=23 c=16
a=12 b=43 c=17 a=63, b=2, c=999
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Perl
Support for objects
use Modulename; $var = Modulename::new(); $var->method(...);
$var->{property};
(include class definition) (instantiate object) (invoke method)
(access property)
Does not have a class keyword, a class is defined as a Perl
module where the functions are invoked as methods and the use of
the bless keyword.
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M/S Scripting Documentation
Script56.chm is the Windows scripting documentation file Local
copy http://www.ae.gatech.edu/classes/ae6 382/MS_scripting/
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JavaScript / JScript
General purpose scripting language Usually appears only in web
browsers Available on most platforms
In Windows Jscript is available as an ActiveX scripting engine,
when run under the Windows Scripting Host it can functions as a
general scripting system Its syntax is very much like C It has
support for objects Limited availability Has limited access to host
system (security feature)
Pros
Cons
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JavaScript / JScript
Variables
Typeless, refer to primitive types and objects Can be arrays
Declared with var statement
Uses the usual set of C operators with some additions Statements
are terminated with ; Comments marked with // and /* ... */
Functions and methods are declared with function name (...) { ...
}
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JavaScript / JScript
Loop statementsvar stdout = WScript.StdOut; var i; for (i=0 ; i
< 10 ; i++) { stdout.WriteLine(i=+i); } var stdout =
WScript.StdOut; var stdin = WScript.StdIn; while (!
stdin.AtEndOfStream) { line = stdin.ReadLine()
stdout.WriteLine(line); } var stdout = WScript.StdOut; var array =
new Array(3); array[0] = 2; array[1] = 12; array[2] = 70; for (var
value in array) { stdout.WriteLine("Value: "+array[value]); }
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JavaScript / JScript
Logical statements
if (i == 5) { stdout.WriteLine(Equality failed); } if (i == 1) {
stdout.WriteLine(Group 1); } else { stdout.WriteLine(Unknown
group); } if (i == 1) { stdout.WriteLine(Group 1); } else if (i ==
2) { stdout.WriteLine(Group 2); } else if (i == 3) {
stdout.WriteLine(Group 3); } else { stdout.WriteLine(Unknown
group); }
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JavaScript / JScript
Regular Expression Supportvar stdout = WScript.StdOut; var stdin
= WScript.StdIn; var re = new RegExp(".*error.*","i"); while (!
stdin.AtEndOfStream) { var line = stdin.ReadLine(); if
(line.match(re)) { stdout.WriteLine(line); } }
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JavaScript / JScript
Regular Expression Supportvar stdout = WScript.StdOut; var stdin
= WScript.StdIn; var re1 = new RegExp("^#","i"); var re2 = new
RegExp(".+a=([0-9]+).+c=([0-9]+)"); var lines = new Array(4);
lines[0] = "# a b c"; lines[1] = " a=10 b=23 c=16"; lines[2] = "
a=12 b=43 c=17"; lines[3] = " a=63, b=2, c=999"; for (var line in
lines) { stdout.WriteLine(lines[line]); if (lines[line].match(re1))
continue; re2.exec(lines[line]); var avalue = RegExp.$1; var cvalue
= RegExp.$2; stdout.WriteLine(avalue+", "+cvalue); }
// lines contains (an array of strings): // # a b c // a=10 b=23
c=16 // a=12 b=43 c=17 // a=63, b=2, c=999
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JavaScript / JScript
Object support
var obj = new Object(); obj.method(...); obj.property;
obj[property];
(instantiate object) (invoke method) (access property) (access
property)
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M/S Scripting Documentation
Script56.chm is the Windows scripting documentation file Local
copy http://www.ae.gatech.edu/classes/ae6 382/MS_scripting/
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VBScript
General purpose scripting language Only available on Windows
Available as an ActiveX scripting engine, when run under the
Windows Scripting Host it has general usage Can be used as the
client-side scripting in IE Simple syntax (Basic) Has support for
objects Windows only
Pros
Cons
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VBScript
Variables
Typeless, refer to primitive types and objects Can be arrays
Declared with Dim statement
Uses a small subset of C operators Statements are terminated by
the end of line Comments marked with (single quote character)
Subroutines Sub name
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VBScript
Loop statementsDim i i = 0 For i=0 To 9 Step 1
WScript.StdOut.WriteLine "i=" & i Next Do While Not
WScript.StdIn.AtEndOfStream Dim line line =
WScript.StdIn.ReadLine() WScript.StdOut.WriteLine(line) Loop Dim d
Set d d.Add d.Add d.Add 'Create a variable =
CreateObject("Scripting.Dictionary") "0", "Athens" 'Add some keys
and items "1", "Belgrade" "2", "Cairo" Do Until
WScript.StdIn.AtEndOfStream Dim line line =
WScript.StdIn.ReadLine() WScript.StdOut.WriteLine(line) Loop
For Each I in d Document.frmForm.Elements(I).Value = D.Item(I)
Next
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VBScript
Logical statements
If i = 5 Then WScript.StdOut.WriteLine Value is & i End If
If i = 1 Then WScript.StdOut.WriteLineGroup 1 Else
WScript.StdOut.WriteLine Unknown group End If If i = 1 Then
WScript.StdOut.WriteLine ElseIf i = 2 Then WScript.StdOut.WriteLine
ElseIf i = 3 Then WScript.StdOut.WriteLine Else
WScript.StdOut.WriteLine End If
Group 1 Group 2 Group 3 Unknown group
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VBScript
Regular Expression Support
Dim re Set re = New RegExp re.Pattern = ".*error.*"
re.IgnoreCase = True Do While Not WScript.StdIn.AtEndOfStream Dim
line line = WScript.StdIn.Readline If re.Test(line) Then
WScript.StdOut.WriteLine line End If Loop
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VBScript
Regular Expression SupportDim line Dim i Dim match Dim re1, re2,
matches, submatches Dim lines(4) lines(0) = "# a b c" lines(1) = "
a=10 b=23 c=16" lines(2) = " a=12 b=43 c=17" lines(3) = " a=63,
b=2, c=999" set re1 = New RegExp set re2 = New RegExp re1.Pattern =
"^#" re2.Pattern = ".+a=([0-9]+).+c=([0-9]+)" For i=0 To 3 line =
lines(i) WScript.StdOut.WriteLine "--> " & line If Not
re1.Test(line) Then ' WScript.StdOut.WriteLine line Set matches =
re2.Execute(line) Set match = matches(0) WScript.StdOut.WriteLine
match.SubMatches(0) & ", " & match.SubMatches(1) End If
Next ' lines contains (an array of strings): ' # a b c ' a=10 b=23
c=16 ' a=12 b=43 c=17 ' a=63, b=2, c=999
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VBScript
Object support
Set obj = New Object obj.method(...) obj.property
(instantiate object) (invoke method) (access property)
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Tcl
General purpose scripting language Available on most
platforms
In Windows it can run standalone an is also available as an
ActiveX scripting engine Interpreter has a small footprint Easily
embedded Extensible using C Strange syntax
Pros
Cons
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Tcl
Variables
Strings are the basic type Can create lists and arrays
Uses the expr command to evaluate expressions Format cmd op op
... op set var value (set counter 5) Reference value: $counter (set
i $counter) Use [ ... ] to evaluate immediately
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Tcl
Loop statementsfor (set i 0} {$i < 10} {incr i 3} { lappend
aList $i } set aList set i 1 while {$i cscript sample1.js
// Get the stdin and stdout descriptors // The WScript object is
created automatically by WSH var stdin = WScript.StdIn; //
properties var stdout = WScript.StdOut; // Get the value to pass to
program stdout.WriteLine("Enter value for i: "); var i =
stdin.ReadLine(); stdout.WriteLine("Enter value for j: "); var j =
stdin.ReadLine(); // Create an instance of the WshShell object (COM
object) var WshShell = new ActiveXObject("WScript.Shell"); // Run
with access to programs I/O var WshScriptExec =
WshShell.Exec("program1"); // Write to the running programs stdio
WshScriptExec.StdIn.WriteLine(" "+i+" "+j); // Wait for the running
program to exit while (WshScriptExec.Status != 1) { ; } // Read
from the running programs stdout var output =
WshScriptExec.StdOut.ReadLine(); stdout.WriteLine("Output from
program: "+output);
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Scripting in Windows
sample1.wsf
execute from cmd prompt> sample1.wsf
// Get the stdin and stdout descriptors // The WScript object is
created automatically by WSH var stdin = WScript.StdIo; //
properties var stdout = WScript.StdOut; // Get the value to pass to
program stdout.WriteLine("Enter value for i: "); var i =
stdin.ReadLine(); stdout.WriteLine("Enter value for j: "); var j =
stdin.ReadLine(); // Create an instance of the WshShell object (COM
object) var WshShell = new ActiveXObject("WScript.Shell"); // Run
with access to programs I/O var WshScriptExec =
WshShell.Exec("program1"); // Write to the running programs stdio
WshScriptExec.StdIn.WriteLine(" "+i+" "+j); // Wait for the running
program to exit while (WshScriptExec.Status != 1) { ; } // Read
from the running programs stdout var output =
WshScriptExec.StdOut.ReadLine(); stdout.WriteLine("Output from
program: "+output);
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Windows Scripting Host
WSH is the context within which VBScript and JScript run
PerlScript and PythonScript are also available Start WSH scripts
using cscript or wscript
cscript - console mode wscript - windows mode, no stdin, stdout,
or stderr
The WSF format can contain several scripts in one text file
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Component Object Model COM
Why use COM The Component Object Model (COM) is the key to
making full use of Windows COM is accessible from C++ and scripting
Scripting an application is called automation Also referred to as
ActiveX and OLE
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Objects in COM
A class defines an object
Properties are variables Methods are functions Each object has
its own copy of the properties When a method is invoked it operates
on only the object that is the target of the invocation
When a class is instantiated an object is created
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Objects in COM
An application can make many classes available for use via COM
The client code (a script for example) must create an instance of
the class (an object) and save a reference in a variable The
applications methods may then be invoked on that object to access
the application Using Windows Script Components (see Script56.CHM)
scripts can be made available to other COM clients via COM
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Objects in COM
Two methods for accessing COM
vtables C/C++ Dispatch scripts
Classes contain properties and methods Collections are classes
that enumerate objects
Dim worksheets, worksheet, excel ... Set worksheet =
excel.Worksheets(sheet1) ... Set worksheet = excel.Worksheets(2)
... excel is an instance of Excel.Application worksheet is an
instance of Worksheet class implied Item method Set worksheet =
excel.Worksheets.Item(2)
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Creating a COM Object Instance
Scripting languages have a mechanism for instantiating a COM
classPerl: use Win32::OLE; ... my $excel =
Win32::OLE->new(Excel.Application); JScript: var excel = new
ActiveXObject(Excel.Application); VBScript: Dim excel Set excel =
CreateObject(Excel.Application); Python: import win32com.client ...
excel = win32com.client.Dispath(Excel.Application);
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Creating a COM Object Instance
Once top level object has been created the remaining hierarchy
is accessed as per the languages normal object mechanism Tcl and
Ruby can also instantiate COM objects
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Object Models
Every COM enabled Windows application has an object model
Requires knowledge of object model to access application
Discovering the object model
Use documentation (Office is documented) Use an object browser
and trial and error
ActiveState Perl includes a simple Object Browser Visual Studio
include an Object Browser
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Example - Perl#!/usr/bin/perl use strict; use use use use
Win32::OLE qw(in with); Win32::OLE::Const 'Microsoft Excel';
Win32::OLE::Variant; Win32::OLE::NLS qw(:LOCALE :DATE);
# Program dies on errors $Win32::OLE::Warn = 3; # The use of '
rather than " is noted my $excel_file =
'c:\latham\ae8801d\perltut.xls'; # Create a connection to Excel #
Try to use an existing object else create a new object my $Excel =
Win32::OLE->GetActiveObject('Excel.Application') ||
Win32::OLE->new('Excel.Application','Quit'); print "ERROR:
",$Win32::OLE::LastError,"\n" if $Win32::OLE::LastError; # Turn off
any alter boxes (such as the SaveAs response)
$Excel->{DisplayAlerts} = 0; # Make Excel visible on the desktop
$Excel->{Visible} = 1; # Add a workbook and save the file my
$Book = $Excel->Workbooks->Add();
$Book->SaveAs($excel_file); # To open an existing file replace
above with # my $Book =
$Excel->Workbooks->Open($excel_file);
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Example Perl# Create a reference to a worksheet my $Sheet =
$Book->Worksheets('Sheet1'); $Sheet->Activate();
$Sheet->{Name} = "sample_sheet"; # Insert some data into the
worksheet my ($mday,$mon,$year) = (localtime(time))[3,4,5]; $year
+= 1900; my $str = $mon.'/'.$mday.'/'.$year;
$Sheet->Range("a1")->{Value} = $str;
$Sheet->Range("c1")->{Value} = "This is a long piece of
text"; # Save $Book->SaveAs($excel_file); # Set cell colors via
a loop foreach my $y (1..56) { my $range = 'b'.$y;
$Sheet->Range($range)->Interior->{ColorIndex} = $y;
$Sheet->Range($range)->{Value} = $y } # Re-format existing
cell my $range = 'A1';
$Sheet->Range($range)->Interior->{ColorIndex} = 27;
$Sheet->Range($range)->Font->{FontStyle} = "Bold";
$Sheet->Range($range)->{HorizontalAlignment} =
xlHAlignCenter; # Set column widths my @columnheaders = qw(A:B);
foreach my $range (@columnheaders) {
$Sheet->Columns($range)->AutoFit(); }
$Sheet->Columns("c")->{ColumnWidth} = 56;
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Example - Perl# Insert borders around cells my @edges =
qw(xlEdgeBottom xlEdgeLeft xlEdgeRight xlEdgeTop xlInsideHorizontal
xlInsideVertical); $range = "b1:c56"; foreach my $edge (@edges) {
with (my $Borders =
$Sheet->Range($range)->Borders(eval($edge)), LineStyle =>
xlContinuous, Weight => xlThin, ColorIndex => 1); } # Insert
a picture my $picture1 =
$Excel->Worksheets('Sheet2')->Shapes->AddPicture('c:\latham\ae8801d\image.jpg',-1,-1,0,0,200,200);
$Excel->Worksheets('Sheet2')->{Name} = "B-17";
#$picture1->{Left} = 100; #$picture1->{Top} = 100; # Save
$Book->SaveAs($excel_file); # Create a chart my $Sheet3 =
$Excel->Worksheets('Sheet3'); my $Chart1 =
$Sheet3->ChartObjects->Add(200,200,200,200);
$Sheet3->{Name} = "Chart Example";
$Chart1->Chart->ChartWizard({Source =>
$Sheet3->Cells(1)});
$Chart1->Chart->SeriesCollection(1)->{Values} =
[19,3,24,56,34,33,16,10,3,100]; # Print a list of the worksheets
foreach my $Sheet (in $Book->{Worksheets}) { print
"Worksheet:\t",$Sheet->{Name},"\n"; } print "Ready to quit"; ;
exit;
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Example - JScript// var fso = new
ActiveXObject("Scripting.FileSystemObject"); var excel = new
ActiveXObject("Excel.Application"); excel.DisplayAlerts = 0;
excel.Visible = 1; var book = excel.Workbooks.Add(); var sheet =
book.Worksheets("Sheet1"); sheet.Activate(); sheet.Name = "sample
sheet"; var wk2 = excel.Worksheets("Sheet2"); var pic1 =
wk2.Shapes.AddPicture("c:\\latham\\ae8801d\\image.jpg",-1,-1,100.,100.,100.,50.);
wk2.Name = "B-17"; pic1.Left = 100; pic1.Top = 100;
WScript.Echo("Hello"); WScript.Sleep(2000);
excel.Worksheets(1).Activate(); WScript.Sleep(2000);
excel.Worksheets(2).Activate(); WScript.Sleep(2000);
excel.Worksheets(3).Activate(); WScript.Sleep(2000); //var stdout =
WScript.StdOut; //var stdin = WScript.StdIn; //var answer =
stdin.ReadLine(); //stdout.WriteLine(answer); excel.Quit(); // var
in = File("stdin"); // fgets(in);
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Example - Pythonimport win32com.client excel =
win32com.client.Dispatch("Excel.Application","Quit")
excel.DisplayAlerts = 0 excel.Visible = 1 book =
excel.Workbooks.Add() sheet = book.Worksheets("Sheet1")
sheet.Activate() sheet.Name = "sample sheet" picture =
excel.Worksheets("Sheet2").Shapes.AddPicture("c:\\latham\\ae8801d\\image.jpg",-1,-1,100.,100.,100.,50.)
excel.Worksheets("Sheet2").Name = "B-17" picture.Left = 100
picture.Top = 100 # Create a chart #sheet =
excel.Worksheets('Sheet3'); #chart1 =
sheet.ChartObjects.Add(200,200,200,200); #sheet.Name = "Chart
Example"; #chart1.Chart.ChartWizard({Source =>
$Sheet3->Cells(1)});
#chart1.Chart.SeriesCollection(1)->{Values} =
[19,3,24,56,34,33,16,10,3,100]; print "Hello from excel1.py" answer
= raw_input("Quit ? ") excel.Quit();
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