Create an executable script¶
Objectives
- Create a Bash script by copy-pasting
- Run a Bash script
Notes for teachers
Teaching goals:
- Learners can create a Bash script by copy-pasting
- Learners can run a Bash script
Prior:
- What is a script?
Feedback:
- What is a script?
- When would you use a script?
Why use scripts?¶
You absolutely need a script to let your calculations be run on Bianca.
Besides that, instead of typing commands in the terminal all the time, you can put these in a file, with the goal of automatic and/or sharing your work.
Procedure¶
As an example, from a terminal on Bianca,
we create a script, called do_it.sh
:
Why use a .sh
file extension?
Using .sh
as a file extension a social convention
for how a Bash script is called,
as (1) sh
is short for 'shell',
(2) Bash is short for 'Bourne Again Shell'.
A 'shell' in this context is a program
that allows working with an operating system.
As an example, copy-paste this content into the script:
What does this program do?
The first line is called the shebang, and indicates this is a Bash script.
The second line displays the text between double quotes.
Save and close nano
.
- Use
CTRL-O
to start saving your file, then edit the filename, then press enter - Use
CTRL-X
to exit
You can run the script with:
Exercises¶
Exercise 1: create a script¶
- On Bianca, create a file called
do_it.sh
usingnano
- Use copy-paste to edit the file
do_it.sh
to have the content below. This script may be small, yours will likely not be, hence use a copy-paste
- Run the script