Introduction to Linux and history

Learning outcomes:

• Create and use a basic shellscript that includes a shebang line, comment and echo
• Explain the different quotes and their uses
• Modify a script using a text editor

Would you like to download my PowerPoint to follow along?

• What is a script and why do we care?
• Small programs that can be used for multiple things including repetitive tasks and repeated activities
• A text file with 1 command per line
• Scripts are also good for Complicated things you don't use often, If you need to figure it out once, why not make a script so you don't have to do it again?
• Comments use a #
• Always start with shbang to specify shell type, it's not required, but it makes it more clear what kind of script you're writing
• An example tutorial for scripting can be found here includes some history of scripting and BASH as well
• Types of text in scripts/li>
  • Plain (no quotes)

    echo hello

  • Semi-opaque (double quotes, expands variables)

    echo "hello $name"

  • Opaque (single quote, shows exactly what's in quotes)

     echo 'hello $name'

• Important things to know
• Backticks

  `this is an example of a backtick`

• Shbang line

  #!/bin/sh

• To run, file must be executable (it's not by default so you will need to change the file permissions There is a video example of me showing how to do that here)
• To run you need to use the path of your script (unless in PATH)
• It is important to TEST YOUR CODE
• Sequence of a successful script
• Test commands at command prompt
• Create and edit the file in an editor (VIM)
• Start script with shbang line ( such as: #!/bin/bash)
• Add comment with function, name and date
• Save
• Change permissions
• Test!!
• Rinse and repeat

Suggested Activities and Discussion Topics:

• Watch this video and follow along to create a shell script.

Would you like to see some more classes? Click here