Hello, World! Tutorial
To create a shell script:
- Use a text editor such as vi. Write required Linux commands and logic in the file.
- Save and close the file (exit from vi).
- Make the script executable.
- You should then of course test the script, and once satisfied with the output, move it to the production environment.
- The simplest program in Bash consists of a line that tells the computer a command. Start up your favorite text editor (such as vi):
Essential Vi Commands
- Open a file:
- To go into edit mode:
press ESC and type I
- To go into command mode:
- To save a file
press ESC and type :w fileName
- To save a file and quit:
press ESC and type :wq
press ESC and type :x
- To jump to a line:
press ESC and type :the line number
- To Search for a string:
Press ESC and type /wordToSearch
- To quit vi:
Press ESC and type :q
Save the following into a file called hello.sh:
#!/bin/bash echo "Hello, World!" echo "Knowledge is power."
Save and close the file. You can run the script as follows:
bash: ./hello.sh: Permission denied
Saving and Running Your Script
The command ./hello.sh displayed an error message on the screen. It will not run script since you've not set execute permission for your script hello.sh. To execute this program, type the following command:
chmod +x hello.sh ./hello.sh
Hello, World! Knowledge is power.