Programming and GUI Fundamentals E-Book

Suman Lata Tripathi

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 261

Veröffentlichungsjahr: 2022

Beschreibung

PROGRAMMING AND GUI FUNDAMENTALS Discover the foundations of TCL programming and GUI development Programming and GUI Fundamentals: Tcl-Tk for Electronic Design Automation (EDA), delivers a comprehensive exploration of the major design challenges and potential present in application and tool development with Tcl-Tk. Accessibly written and easy-to-understand, the book can be used by students at a variety of levels, as well as researchers and working professionals. The authors present the fundamental concepts of Tcl programming and graphic user interface (GUI) development using images, and photographs, assisting with concept understanding and retention. They describe real-time system designs and offer students and designers the opportunity to learn about critical concepts in scripting and GUI development. Readers will learn to design their own GUI, place and package widgets on the GUI, and allow EDA professionals, chip designers and students to code and design in TCL-TK. They will also benefit from: * A thorough introduction to scripting languages and wish interpreters, including their fundamental concepts, TCL tips and tricks, and command, variable, and procedure examples * Comprehensive explorations of the TCL data structure, including datatypes, strings and commands, lists and commands, and arrays and commands * Practical discussions of TCL control flow, including conditional commands, multi-condition commands, and loop commands * In-depth examinations of file input/output processing, including TCL file read-write, open and close commands, gets, and puts. Perfect for undergraduate and graduate students studying programming or computer science, as well as professionals working on electronic design automation and chip design, Programming and GUI Fundamentals: Tcl-Tk for Electronic Design Automation (EDA) is also an indispensable resource for programming professionals seeking to upskill.

Leseprobe

Table of Contents

Cover

Title Page

Copyright

About the Authors

1 Introduction

1.1 Features of Tcl

1.2 Special Variable

1.3 Tcl First Program

1.4 Tcl Identifiers

1.5 Applications of Tcl

References

2 Basic Commands

2.1 Introduction

2.2 Set Command

2.3 Variable Substitution

2.4 Grouping

2.5 Command Substitution

2.6 Math Expressions

2.7 Backslash Substitution (

\&

)

2.8 Tcl Operator

2.9 Procedure

2.10 Eval Commands

2.11 Solved Questions

2.12 Review Questions

2.13 MCQs Based on Tcl Basics

References

2.A Appendix I (Built‐in math functions)

2.B Appendix II (Tcl Backslash sequence)

3 Program Flow Control

3.1 If–Else Command

3.2 Switch‐Case Command

3.3 Loop Command

3.4 Continue and Break

3.5 Catch and Error

3.6 Solved Problems

3.7 Practice Questions

3.8 MCQs

References

4 Tcl Data Structure

4.1 String and Matching Command

4.2 Lists and their Commands

4.3 Arrays and their Commands

References

5 Tcl Object‐Oriented Programming

5.1 Class

5.2 Creation of a Class

5.3 Define a Member in a Class

5.4 Define Method

5.5 Constructor and Destructor

5.6 Destroying of Class

5.7 Invoking Method

5.8 Registering Method for Callback

References

6 File Processing

6.1 Introduction

6.2 Tcl File Command

6.3 Tcl File In‐built Commands

6.4 Solved Questions

6.5 Review Questions

6.6 MCQs based on Tcl File Processing

References

7 Toolkit Widgets

7.1 Features of Tk Widgets

7.2 Geometry Manager

7.3 Widget Naming

7.4 Widget Dimension

7.5 Widget Configuration

7.6 Widget Programming

7.7 Solved Problems

7.8 Unsolved Problems

7.9 MCQs on Tk Widgets

References

8 Binding Commands and Other Widgets

8.1 Class and Widget Binding

8.2 Widget Characteristic Commands

8.3 Menubar‐Menu‐Menubutton

8.4 Tearoff Command

8.5 Listbox Widget

8.6 Place Manager

8.7 Solved Problems

8.8 MCQs on Bind, Menu, and Place Manager

References

9 Canvas Widgets and Tk Commands

9.1 Canvas Coordinate

9.2 Drawing over Canvas

9.3 Event Binding of Canvas Object

9.4 Create a Movable Object

9.5 Tk built‐in Command

9.6 Solved Problems

9.7 Review Problem

9.8 MCQs of Canvas

9.A Appendix A

References

10 Tcl‐Tk for EDA Tool

10.1 Accessing Vivado Tool via Tcl Script

10.2 Sourcing the Tcl Script with Vivado

10.3 Implementing Counter Program with Vivado Tcl Console

10.4 Advantage of Vivado in Tcl Mode

Reference

10.A Appendix

Index

End User License Agreement

List of Tables

Chapter 1

Table 1.1 Programming and scripting language comparison.

Chapter 2

Table 2.1 Arithmetic operator.

Table 2.2 Relational operator.

Table 2.3 Logical operator.

Table 2.4 Bitwise operator.

Table 2.5 Shift operator.

Table 2.6 Operator precedence order.

Chapter 4

Table 4.1 String‐based command.

Table 4.2 Format specifier.

Table 4.3 List‐based command.

Table 4.4 Arrray command in Tcl.

Chapter 6

Table 6.1 Access mode of Tcl file.

Table 6.2 Tcl file in‐built command.

Chapter 7

Table 7.1 Tk widget command.

Table 7.2 Widget configuration.

Table 7.3 Scale commands.

Chapter 8

Table 8.1 List of event generation.

Table 8.2 Attributes to menu.

Table 8.3 Attributes to menubutton.

Chapter 9

Table 9.1 Attributes to the canvas.

Table A.1

Tk

in‐built command.

Chapter 10

Table 10.1 Command to access Vivado Tool.

List of Illustrations

Chapter 1

Figure 1.1 Command‐line interpreter.

Figure 1.2 Wish interpreter.

Figure 1.3 Tkcon interpreter.

Figure 1.4 Tcl special variable.

Figure 1.5 Tcl simple program.

Chapter 2

Figure 2.1 Tclsh screen.

Figure 2.2 Wish screen.

Figure 2.3 The

puts

command in Tcl.

Figure 2.4 The

puts

command with (\) sequence.

Figure 2.5 Variable declarations with the

set

command.

Figure 2.6 Variable substitution.

Figure 2.7 Substitution with grouping.

Figure 2.8 Command substitution.

Figure 2.9 Nesting of commands.

Figure 2.10 Math expressions with the

expr

command.

Figure 2.11 Disable substitution.

Figure 2.12 Arithmetic operator.

Figure 2.13 Relational operator.

Figure 2.14 Logical operator.

Figure 2.15 Bitwise operator.

Figure 2.16 Ternary operator.

Figure 2.17 Shift left and shift right.

Figure 2.18 Addition with the procedure.

Figure 2.19 Using

proc

with default variable.

Figure 2.20 The

eval

command.

Figure 2.21 Temperature conversion with

proc

.

Figure 2.22 Random number generation with

rand()

function.

Figure 2.23 Using

proc

to find the maximum of two numbers.

Figure 2.24 Factorial computation using

proc

.

Chapter 3

Figure 3.1

If–else

condition flowchart.

Figure 3.2

If–elseif–else

condition flowchart.

Figure 3.3

Switch

case flowchart.

Figure 3.4

While

loop flowchart.

Figure 3.5 Flowchart of

for

loop.

Figure 3.6

Foreach

command flowchart.

Chapter 4

Figure 4.1 String declaration.

Figure 4.2 String basic command.

Figure 4.3 String trim.

Figure 4.4 String case.

Figure 4.5 String compare.

Figure 4.6 String append.

Figure 4.7 Format command example.

Figure 4.8 Format command with precision.

Figure 4.9 Decimal to other formats.

Figure 4.10 Octal to other formats.

Figure 4.11 Binary to other formats.

Figure 4.12 Hexadecimal to other formats.

Figure 4.13 Scan command example.

Figure 4.14 Clock seconds example.

Figure 4.15 Time representation with clock format.

Figure 4.16 Clock format with predefined template.

Figure 4.17 Clock format to display system time.

Figure 4.18 Clock scan.

Figure 4.19 Clock add.

Figure 4.20 List declaration.

Figure 4.21 List created in Tcl console.

Figure 4.22 Element‐based list command.

Figure 4.23 String as an element of the list.

Figure 4.24

linsert

example.

Figure 4.25

lreplace

example.

Figure 4.26

lsearch

example.

Figure 4.27

lassign

example.

Figure 4.28

lsort

example.

Figure 4.29 Split and join example.

Figure 4.30 Array initialization by array command.

Figure 4.31 Array initialization by setting elements.

Figure 4.32 Array index as an alphanumeric character.

Chapter 5

Figure 5.1 Destroying of class.

Chapter 6

Figure 6.1 Tcl script to open a file with extension.

Figure 6.2 Result of Figure 6.1.

Figure 6.3 Tcl script to close a file.

Figure 6.4 Tcl script to write with the

puts

command.

Figure 6.5 Tcl script to write multiple statements with the

puts

command.

Figure 6.6 File available in the directory.

Figure 6.7 Tcl script for a single statement.

Figure 6.8 © Tcl script for multiple statements.

Figure 6.9 Tcl script to read the file in a loop.

Figure 6.10 Tcl script for the

read

command

Figure 6.11 Previous content in the file.

Figure 6.12 Result after appending.

Figure 6.13 File‐based in‐built commands with examples.

Figure 6.14 Initial content in a file.

Figure 6.15 Execution result of file access by the

list

command.

Figure 6.16 Writing with the

puts

command.

Figure 6.17 Reading with the

gets

command.

Figure 6.18 Earlier content written in the file.

Figure 6.19 Execution result of the

read

inside the loop.

Figure 6.20 Integer already written in the file.

Figure 6.21 Execution result of

read

command.

Figure 6.22 Content of file one.csv to be read.

Figure 6.23 Content written in two.csv.

Figure 6.24 Random number written in the file.

Figure 6.25 Initial measurement of experiments.

Figure 6.26 Result of the script.

Chapter 7

Figure 7.1 Button widget.

Figure 7.2 Multiple widgets on screen.

Figure 7.3 Button with the

puts

command.

Figure 7.4 Button with the

exit

command.

Figure 7.5 Button and different attributes.

Figure 7.6 Label widget.

Figure 7.7 Label with different attributes.

Figure 7.8 Button with config.

Figure 7.9 Label with config.

Figure 7.10 Sum in a label.

Figure 7.11 Entry for user input.

Figure 7.12 Entry with textvariable.

Figure 7.13 Entry space with a hidden character.

Figure 7.14 Frame widget.

Figure 7.15 Buttons in horizontal and vertical arrangements.

Figure 7.16 Scale orientation.

Figure 7.17 Slider on a scale.

Figure 7.18 Scale with procedure.

Figure 7.19 Message text on multiple lines.

Figure 7.20 Product with a spinbox widget.

Figure 7.21 GUI for random number generation.

Figure 7.22 Scale with procedure.

Figure 7.23 GUI of the half adder.

Figure 7.24 GUI of the full adder.

Figure 7.25 GUI of a calculator.

Figure 7.26 GUI of a power calculation.

Figure 7.27 Message justified with the aspect ratio.

Chapter 8

Figure 8.1 Before event.

Figure 8.2 After event.

Figure 8.3 Before event.

Figure 8.4 After event.

Figure 8.5 Before event.

Figure 8.6 After event.

Figure 8.7 Before event.

Figure 8.8 After event.

Figure 8.9 Horizontal scale scrollbar movement maps of keysym.

Figure 8.10 Button‐label on Frame‐1.

Figure 8.11 Button‐label on Frame‐2.

Figure 8.12 Remove button from Frame‐1.

Figure 8.13 Remove label from Frame‐2.

Figure 8.14 Remove Frame‐1.

Figure 8.15 Arrange a button on the right side.

Figure 8.16 Horizontal stack.

Figure 8.17 Vertical stack.

Figure 8.18 Remove button from Frame‐1.

Figure 8.19 Widget showing cavity on frame.

Figure 8.20 Widget with

–fill

command.

Figure 8.21 Widget with

–expand

command.

Figure 8.22 Button with ipad.

Figure 8.23 Direction with anchoring.

Figure 8.24 Anchoring of label.

Figure 8.25 Creation of menu for menubutton.

Figure 8.26 Adding entries to menu.

Figure 8.27 Menu with separator.

Figure 8.28 Tcl command associated with menu entry.

Figure 8.29 Creation of submenu.

Figure 8.30 Command link to menu and submenu.

Figure 8.31 Configuring menu entries.

Figure 8.32 Creation of pop‐up menu.

Figure 8.33 Creation of listbox.

Figure 8.34 Listbox with select mode.

Figure 8.35 Relation position range.

Figure 8.36 Absolute positioning with place manager.

Figure 8.37 Relative positioning with place manager.

Figure 8.38 Before event.

Figure 8.39 Event on binary.

Figure 8.40 Event on octal.

Figure 8.41 Event on hexadecimal.

Figure 8.42 Calculator before input.

Figure 8.43 Calculator with the result.

Figure 8.44 Creation of button with

for

loop.

Figure 8.45 GUI of the calculator with scale input.

Figure 8.46 Two menubuttons.

Figure 8.47 Menu of menubutton‐1.

Figure 8.48 Menu of menubutton‐2.

Figure 8.49 Submenu.

Figure 8.50 Place manager with relation position.

Chapter 9

Figure 9.1 Canvas with background color.

Figure 9.2 Arc on the canvas.

Figure 9.3 Line on the canvas.

Figure 9.4 Rectangle on the canvas.

Figure 9.5 Polygon on the canvas.

Figure 9.6 Oval on the canvas.

Figure 9.7 Text on the canvas.

Figure 9.8 Bitmap.

Figure 9.9 Bitmap on the canvas.

Figure 9.10 Image in the directory.

Figure 9.11 Image on the canvas.

Figure 9.12 Image in the directory.

Figure 9.13 Image on the canvas.

Figure 9.14 Image dimension adjustment.

Figure 9.15 Image dimension for each image.

Figure 9.16 Objects on the canvas.

Figure 9.17 Circle using arcs.

Figure 9.18 Bounded text widget.

Figure 9.19 Bounded text widget at different locations on the canvas.

Figure 9.20 Movable oval on the canvas

Figure 9.21 Movable oval and line on the canvas.

Figure 9.22 Movable image on the canvas.

Figure 9.23 Object on the canvas via

eval

command.

Figure 9.24 GUI before event.

Figure 9.25 GUI during first event.

Figure 9.26 GUI during second event.

Figure 9.27 GUI after both events.

Figure 9.28 Before event.

Figure 9.29 Pop‐up dialog box.

Figure 9.30 After event.

Figure 9.31 Before event.

Figure 9.32 Pop‐up dialog box to select the file.

Figure 9.33 After event.

Figure 9.34 Message box before response.

Figure 9.35 Message box after selecting No.

Figure 9.36 Sine wave.

Figure 9.37 Square wave.

Figure 9.38 Symbolic library interface.

Figure 9.39 Function on the canvas.

Figure 9.40 Canvas clear function

Figure 9.41 Progressbar before event.

Figure 9.42 Progressbar after event.

Chapter 10

Figure 10.1 Homepage of Vivado Design Suite.

Figure 10.2 Vivado interface after creating project.

Figure 10.3 Adding FA module.

Figure 10.4 Adding stimulus file.

Figure 10.5 Adding constraint file.

Figure 10.6 Synthesize project summary.

Figure 10.7 FPGA package view.

Figure 10.8 Testbench waveform.

Figure 10.9 Power report.

Figure 10.10 Timing report.

Figure 10.11 Utilization report.

Figure 10.12 Datasheet report.

Figure 10.13 Source and constraint file of full subtractor.

Figure 10.14 Sourcing a .tcl script.

Figure 10.15 Simulation waveform of FS.

Figure 10.16 Utilization reports of FS.

Figure 10.17 Timing report of FS.

Figure 10.18 Power report of FS.

Figure 10.19 Datasheet report of FS.

Figure 10.20 Source and constraint file of counter.

Figure 10.21 Sourcing of counter.tcl.

Figure 10.22 Simulation waveform of the counter.

Figure 10.23 Utilization report of counter.

Figure 10.24 Power report of counter.

Figure 10.25 Timing report of counter.

Figure 10.26 Datasheet report of counter.

Guide

Cover

Table of Contents

Title Page

Copyright

About the Authors

Begin Reading

Index

End User License Agreement

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Programming and GUI Fundamentals

Tcl‐Tk for Electronic Design Automation (EDA)

Suman Lata TripathiLovely Professional UniversityPhagwara, India

Abhishek KumarLovely Professional UniversityPhagwara, India

Jyotirmoy PathakLovely Professional UniversityPhagwara, India

Copyright © 2023 by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.

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About the Authors

Dr. Suman Lata Tripathi received her Ph.D. in the area of microelectronics and VLSI from MNNIT, Allahabad. She received her M.Tech in Electronics Engineering from UP Technical University, Lucknow, and her B.Tech in Electrical Engineering from Purvanchal University, Jaunpur. She is a Professor at Lovely Professional University and has more than seventeen years of experience in academics. She has published more than 74 research papers in refereed journals and conferences. She has organized several workshops, summer internships, and expert lectures for students. She has worked as a session chair, conference steering committee member, editorial board member, and reviewer in international/national IEEE journals and conferences. She has received the “Research Excellence Award” in 2019 and “Research Appreciation Award” in 2020, 2021 at Lovely Professional University, India. She received the best paper award at IEEE ICICS‐2018. She has published the edited books Recent Advancement in Electronic Devices, Circuit, and Materials; Advanced VLSI Design and Testability Issues; and Electronic DevicesandCircuit Design Challenges for IoT Application. She is also an editor of the book series on Green Energy: Fundamentals, Concepts, and Applications and Design and Development of Energy Efficient Systems, which are yet to be published. She is currently working on an accepted book proposal specifically on Electronic Device and Circuits Design Challenges to Implement Biomedical Applications. She is working as a series editor for a title,Smart Engineering Systems.

Her area of expertise includes microelectronics device modeling and characterization, low power VLSI circuit design, VLSI design of testing, advanced FET design for IoT, embedded system design, biomedical applications, etc.

Mr. Jyotirmoy Pathak has completed his post graduation in VLSI Design and graduation in Electronics and Communication Engineering from Anna University, India. He holds more than 10 research papers in a refereed journal. He holds 9 patents and 1 copyright. He has been the reviewer of many journals such as the IETE Journal of Research etc. He has also played the role of session chair for many international conferences.

His area of expertise includes VLSI signal processing, hardware security, FPGA prototype development, and low power ASIC design.

Dr. Abhishek Kumar obtained his Ph.D. in the area of VLSI Design for Low Power and Secured Architecture from Lovely Professional University, India. He received his M.Tech in Electronics Engineering from the University of Mumbai, India, and graduated from The Institution of Engineers (India). He has been an Associate Professor at Lovely Professional University for 11 years. He has published more than 35 research papers in refereed journals and conferences. He has organized workshops, summer internships, and expert lectures for students. He has worked as a session chair, conference steering committee member, editorial board member, and reviewer in international/national journals and conferences. He has published the book Intelligent Green Technologies for Sustainable Smart Cities with Wiley‐Scrivener and another book Machine Learning Technique with VLSI is in production with Wiley‐Scrivener.

His area of expertise includes VLSI design, low power architecture, memory design, data converters, ASIC‐SoC, cryptology, and side channel attacks.

1Introduction

Language is a structured system of communication used by humans. When a human wishes to communicate with a computer system, a programming language is required. A programming language is able to convert a set of instructions, known as the source code, to perform a specific task. There are a number of common programming languages, such as C, C++, and JAVA. Each programming language requires a specific compiler, which is able to translate the source code into machine code. There are also other mechanisms to produce machine code that are interpreter‐based, and these use step‐by‐step executors of the source code. A language can be implemented with either a compiler or interpreter. A combination of both platforms is possible too where the compiler generates the machine code and then passes it to the interpreter for execution [1].

Tcl stands for Tool Command Language. It is an interpreter‐based scripting language, designed to be easy to embed into the application. A scripting language is a programming language that automates the execution of tasks. Scripts are written for the run time execution and are interpreted rather than compiled. Some popular scripting languages are Python, Ruby, Bash, Node Js, and Perl. Scripting languages are required in web applications, system administration, gaming, and plugin development for an existing system. Scripting languages are preferred owing to the (i) ease of learning, (ii) fast editing, (iii) interactivity, and (iv) functionality.

The shell script is a set of instructions in the specific programming language to be run by the UNIX shell, a command‐line interpreter. Tcl (pronounced as tickle) is high‐level, interpreted, dynamic programming. Tcl is very similar to the UNIX shell languages, namely Bounce, C, Korn, and Perl, and therefore offers a wide range of programmability [2]. Tcl supports a wide range of programming paradigms, like object‐oriented programming, and the imperative and functional procedural styles offer the ability for applications to communicate with each other. It is possible to associate Tcl with the toolkit (Tk) used for building a graphical user interface (GUI). Tk is a cross‐platform, which offers a wide range of widget libraries that can also be associated with other programming languages.

Tcl and the X‐window toolkit were developed by Prof. John Ousterhout of U.C. Berkeley to solve the difficulty associated with a programming language. It was initially developed for UNIX, then ported to Windows, MAC, DOS, and QS/2. Its ability to integrate a Tcl interpreter with existing applications and to interact with the program set is what differentiates it from other programs. Table 1.1 presents a comparison between programming and scripting languages.

Table 1.1 Programming and scripting language comparison.

Programming language

Scripting language

Set of instructions executes a task

Based on script written for run time environment

Compiler based

Interpreter based

Develop from scratch

Can integrate with existing

Run independent of parent program

Run inside another program

Compiled into a more compact form, does not need to be interpreted

Can be interpreted within another program

Offer full usage of language

Faster execution

One‐shot conversion

Line‐by‐line conversion

Long development time

Shorter development time since less coding

C, C++, C#, Java, VB, COBOL, PASCAL

JavaScript, Tcl, Perl, PHP, Ruby, Lua, Shell

1.1 Features of Tcl

Low development time

Easy integration with Tk

Cross‐platform independence can access with Windows, Mac, Unix

Inclusion into another programming languages

Open‐source

Command‐based operation

Dynamically redefined and overridden

Data types are based on strings

Event‐driven interface

A Tcl application requires a Tcl interpreter and a text editor. Nomenclature and version of the editor would be different depending on the operating system. Vi is preferred for UNIX or LINUX systems and notepad for Windows as a .tcl file. A Tcl script development with a text editor must be saved with the extension .tcl, which is known as the source file. The interpreter enables us to execute the Tcl command line by line. The latest version of the Tcl installer for the Windows operating system can be downloaded from http://activestate.com. The latest stable version is tcl8.6.

There is a different mechanism to access the Tcl interpreter

Search ➔ tclsh

Figure 1.1 shows a command‐line interpreter based on the Windows environment.

Figure 1.1 Command‐line interpreter.

Search ➔ wish

Figure 1.2 Wish interpreter.

Wish, i.e., Windowing Shell, is a Tcl interpreter, as presented in Figure 1.2, embedded with Tk; the Tcl command is read from a standard text editor or notepad. The Tcl command can be edited in the console window and wish in a smaller window to display the Tk widget. Alternatively, users can interact via importing the source file into the interpreter. A set of Tcl commands edited with notepad saved with the .tcl extension can be imported into the console.

File ➔ Source ➔ locate the file ➔ open search ➔ tkcon

Figure 1.3 Tkcon interpreter.

The tkcon interface shown in Figure 1.3 is a replacement of the standard console with Tk. It provides a GUI while the Tk commands are used in the program. Users can enter the program using a standard text editor or can import a source file.

File ➔ Load file ➔ Locate the file ➔ Open

1.2 Special Variable

Tcl includes some special variables that present their usage (see Figure 1.4). The following is a list of the special variables [3].

tcl_library

Sets the location of Tcl library.

tcl_version

Displays the current version of the interpreter.

tcl_patchLevel

Displays the current patch level.

tcl_interactive

Switches between interactive (1) and non‐interactive (0) mode.

tcl_precision

Displays the number of digits to generate when converting floating‐point values to strings.

tcl_rcFileName

Provides the user‐specific startup file.

tcl_pkgPath

Provides a list of directories where packages are installed.

Argc

Refers to several command‐line arguments.

Argv

Refers to the list containing the command‐line arguments.

argv0

Refers to the filename being interpreted.

env (PATH)

When Tcl starts, it creates the env array and reads the environment. It displays the array of elements for the environment variable.

Figure 1.4 Tcl special variable.

Tk is the most common extension of Tcl, and enables the creation and manipulation of the interface widgets. Advantages of the GUI design with command‐line arguments are (i) faster development, (ii) a higher level of interface than other standard library toolkits, (iii) interface can be factorized with user application.

The following online platforms prove that an online interpreter does not need to be installed:

https://onecompiler.com/tcl

https://rextester.com/l/tcl_online_compiler

https://ideone.com/l/tcl

1.3 Tcl First Program

The following Tcl script displays a statement at the std. output [4]:

puts “Hello Tcl World”

Each line of the script can be terminated by a newline or semicolon (;). A script can be stopped from execution via commenting by adding a hash (#) at the beginning. Figure 1.5 displays a simple program to display.

Figure 1.5 Tcl simple program.

1.4 Tcl Identifiers

Tcl is a case‐sensitive language. Identifiers are the names used to identify the variable (defined by the user). An identifier can start with an alphabetical letter (A–Z/a–z), underscore (_), or numeric digit (0–9). It avoids characters such as @ and %.

Examples: var., Var, St1, s_1, prog50.

Whitespace in Tcl is known as a blank statement and the interpreter ignores it. Whitespace describes the blank, newline, tab character, or comment. It separates one part of the statement from another.

1.5 Applications of Tcl

There are several reasons a developer may prefer a Tcl scripting language. The following are the most favorable applications for the Tcl language.

Cross‐platform application

Graphical user interface development

Software testing via API of the application

Scalable website

Embedded application

Web‐server hosting

References

1.

https://www.tcl.tk/software/tcltk/choose.html

2.

https://www.tutorialspoint.com/tcl-tk/index.htm

3.

https://www.activestate.com

4. Beebe, N.H. (2013).

A Bibliography of O'Reilly & Associates and O'Reilly Media. Inc. Publishers

. Department of Mathematics, University of Utah.

2Basic Commands

2.1 Introduction

Tcl is a script‐based language that was developed by John Osterhout in 1989 (University of California, Berkeley). It has a lower number of keywords and syntax compared with others making it easy to learn. Windows‐based Tcl shells can be used as tclsh or wish, as shown in Figures 2.1 and 2.2, respectively. The first is similar to a C‐shell while the second is a Tcl interpreter that extends its Tk command to create and manipulate widgets. The console window executes the Tcl program and the graphical user interface (GUI) developed with Tk widgets appears in the wish window. Console and wish are intractable. Both shells print a % prompt and execute the Tcl command and print the result sequentially. A Tcl program saves with an extension of .tcl.

Figure 2.1 Tclsh screen.

The basic syntax of a Tcl program is

Command arg1, arg2,…………. Argn