Your First Bash Script

A Bash script is a plain text file containing commands, with a special first line that tells the system which interpreter to use.

Create your first script

nano hello.sh

Type the following, then save and exit (Ctrl+O, Ctrl+X in nano):

#!/bin/bash

echo "Hello, world!"
echo "Today is $(date +%A)"

• The first line #!/bin/bash is the shebang — it tells Linux to run this file with the Bash interpreter
• echo prints text
• $(...) runs a command and inserts its output — here, date +%A prints the current weekday

Make it executable

A script will not run just because it is a text file. Give it the execute bit you learned about in the permissions tutorial:

chmod +x hello.sh

Run it

./hello.sh

Alternative: run it with bash

You can also run any script without making it executable by passing it to Bash directly:

bash hello.sh

Add a comment

# starts a comment — anything after it is ignored:

#!/bin/bash
# This is my first script
echo "Hello, world!"

Try it

1. Create hello.sh exactly as above
2. chmod +x hello.sh && ./hello.sh
3. Change the date command and run it again