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Bash Scripting

Why Scripting?

Computers don't do what you want
They do what you tell them do do

To clear up some confusion you might have, let's get a definition of what scripting is in this environment.

Scripting generally is programming, but on a slightly smaller scale, and a different purpose. Programs (or applications like the web browser you are using now) consist of thousands of lines of code (perhaps written by a team) in C or Pascal or Swift, which then have to be compiled before they are useful.

We are going to use the commands available to us in the bash shell. Scripts are usually smaller projects, with a more specific job, but can still be quite complex.

All scripts begin with source code, which are commands written in a text file to perform various operations. To run or execute the commands, we can now simply refer to the file we put them in, instead of entering them individually.

And, scripts are useful right away. If you need or want more help with programming visit my Digital Knowledge Base and search for 'Programming'.

If you've spent some time working with CLI in Terminal, you may have asked 'What's the advantage to scripting?'.

Here's a few good reasons why you might consider it:

you can perform operations normally requiring more work when using just the CLI
reduce or eliminate typos and syntax errors
you can reuse the script, or pass it on
scripts can be automated to run at specific times
scripts can perform complicated logic and 'what if' scenarios
all the steps in a series of commands are now recorded, so can be used for debugging and auditing
a script can perform hundreds of statements in a loop

Use the CLI for those quick one-off jobs, ad-hoc queries, or troubleshooting.
Use a script for repetitive or complex jobs, or monitoring.

Since we're talking bash here, the commands we will be using are usually built-in commands or executable commands available to bash.

It generally means saving those commands in a file, (in a particular order), then executing that file to do the job, rather than entering the commands on the Command Line.

A good understanding of the commands available to you is essential - how do you ask for a coffee if you don't know the language?

If you've gone through the links up to here, you should be ready for some real work.

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