Coding Hello World in Bash
Here’s a basic Hello World in Bash that includes a simple function such that it could be sourced from your
But First …
Step by Step
cd to a place to create your Bash files. Usually this will be your
cd cd repos/codebook
💬 Remember that
cdwith no arguments just takes you home.
Now make a directory for your Bash scripts and change into it.
mkdir bash cd bash pwd
Notice that there is nothing in here (as expected).
touch a file to create it.
touch hello ls -l
-rw-r--r-- 1 rob rob 0 May 17 19:07 hello
Notice that those permissions don’t have any
x in them. That will be something we deal with later. For now, this is just a readable and writable text file like any other.
Let’s open it up and edit it. Use
vi hello or
code -r . depending on your preference.
Now add the following simple
echo hello world
Notice you don’t need anything but
world. This is a special way that
echo makes it really easy to print stuff out to the terminal command line.
Now let’s run it.
Exit your editor or open another terminal.
You might be wondering why
bash is needed. Our text file
hello is just a text file. We need to make it into a script.
To do this we first have to change the permission mode on the file. Here’s how. The
ls -l will show us the changes.
chmod +x hello ls -l hello
-rwxr-xr-x 1 rob rob 18 May 17 19:56 hello
xs in everything.
Maybe you also noticed that the color of the file changed, this is because you terminal is help you out by showing you scripts and programs that can be executed.
Now that it has execute permission you can just run it without
bash in front. But we still have to indicate we want to run this script right here. That is what the
You should see it work.
There’s one last thing we should always do for scripts. It’s called the shebang line.
Open your script up again and add the following to the first line. Put a blank line for good style.
#!/bin/bash echo hello world
Now close and run it again.
Congratulations you have written your first Bash script!