Creating a script file (.sh) in Bash Scripting - Visual Walkthrough

Concept Flow - Creating a script file (.sh)

Open text editor

↓

Write script lines

↓

Save file with .sh extension

↓

Make file executable

↓

Run script in terminal

↓

See output or result

This flow shows how to create a shell script file, make it executable, and run it to see the output.

Execution Sample

Bash Scripting

#!/bin/bash

echo "Hello, world!"

This script prints 'Hello, world!' to the terminal when run.

Execution Table

Step	Action	Command/Code	Result/Output
1	Open text editor	nano hello.sh	Text editor opens with new file
2	Write script lines	#!/bin/bash echo "Hello, world!"	Script content written in editor
3	Save file	Ctrl+O then Enter	File 'hello.sh' saved
4	Exit editor	Ctrl+X	Back to terminal
5	Make file executable	chmod +x hello.sh	File permission changed to executable
6	Run script	./hello.sh	Hello, world!
7	End	Script finished running	Terminal prompt returns

💡 Script runs once and ends after printing the message.

Variable Tracker

Variable	Start	After Step 2	After Step 5	After Step 6
script_file	none	hello.sh content written in editor	hello.sh marked executable	script executed, output shown

Key Moments - 3 Insights

Why do we add #!/bin/bash at the top of the script?

This line tells the system to use the bash shell to run the script, as shown in execution_table step 2.

Why do we need to run chmod +x before running the script?

chmod +x makes the script file executable, allowing the system to run it, as seen in execution_table step 5.

What happens if we try to run the script without ./ before the filename?

The system may not find the script because current directory is not in PATH; using ./hello.sh runs it explicitly, shown in step 6.

Visual Quiz - 3 Questions

Look at the execution table, what command makes the script file executable?

A ./hello.sh

B chmod +x hello.sh

C nano hello.sh

D echo "Hello, world!"

💡 Hint

Check step 5 in the execution_table where file permissions change.

At which step does the script actually run and print output?

A Step 2

B Step 4

C Step 6

D Step 1

💡 Hint

Look for the step where './hello.sh' is executed and output appears.

If you forget to add #!/bin/bash at the top, what might happen?

A Script may run with a different shell or error

B Script runs normally without any issue

C chmod +x will fail

D File won't save

💡 Hint

Refer to key_moments about the purpose of the shebang line.

Concept Snapshot

#!/bin/bash at top tells system to use bash
Write commands in plain text editor
Save file with .sh extension
Make executable with chmod +x
Run script with ./filename.sh
Script runs and shows output in terminal

Full Transcript

To create a shell script file, first open a text editor like nano. Write your script lines, starting with #!/bin/bash to specify the shell. Save the file with a .sh extension, for example hello.sh. Exit the editor and make the file executable by running chmod +x hello.sh in the terminal. Finally, run the script by typing ./hello.sh. The script will execute and print its output, such as 'Hello, world!'. This process ensures your script runs correctly in the bash shell.