Tcl is a general purpose multi-paradigm system programming language. It is a scripting language that aims at providing the ability for applications to communicate with each other. On the other hand, Tk is a cross platform widget toolkit used for building GUI in many languages. This tutorial covers various topics ranging from the basics of the Tcl to its scope in various applications.
Here are some features of TCl programing language:
1) Rapid development: The most important reason why people use Tcl is that it gets their job done faster. In many cases you can implement applications 5-10x faster with Tcl than with other languages, especially if the application involves GUIs, string-handling, or integration.
2) Graphical user interfaces: With its Tk toolkit, Tcl provides facilities for creating GUIs that are incredibly simple yet remarkably powerful. For example, the Tk canvas widget makes it easy to create displays with graphics, yet it also provides powerful facilities such as bindings and tags.
3) Easy to learn: Tcl is a very simple language. Experienced programmers can learn Tcl and produce their first interesting application in just a few hours or days. Casual programmers can also learn Tcl quickly.
To verify the installation, follow the below instructions
Step 1. Connect to SSH:
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Instances.
Select the instance and choose Connect.
Choose SSH Client
Copy the SSH command and paste it into the terminal.
ssh admin@publicIP -i [Path of key pair file]
If it shows an access denied message run the following command, then run the above command again to connect via ssh.
chmod 400 [Path of key pair file]
Once launched in the Amazon EC2 Service, please connect to the instance via an SSH client using the ec2-user with the key pair associated at launch. Once connected as the ec2-user user, you will be able to sudo to the root user
Step 2. Verify the installation
Follow the steps to verify the Tcl installation
1. Login with ssh
2. Type the below command to check version
echo 'puts $tcl_version;exit 0' | tclsh
You will see the responses as shown below.
How to use Tcl language in the terminal:
1. After connecting with ssh write the below command:
sudo nano helloworld.tcl
2. After that paste the code in the file given below :
3. Run the below command:
4. If you get the Hello, World! in output then your Tcl is working properly.
To monitor and assess application functions:-
a. Navigate to your Amazon EC2 console and verify that you're in the correct region.
b. Choose Instances and select your launched instance.
c. Select the server to display your metadata page and choose the Status checks tab at the bottom of the page to review if your status checks passed or failed.
For information about how to use the application, please visit: https://www.tutorialspoint.com/tcl-tk/index.htm
For detailed information about managing and requesting increased service please visit: https://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html