GitHub Actions can be used to do something whenever something happens in one of your GitHub repositories. If you are not familiar with GitHub Actions, check out my article Getting Started with GitHub Actions.

If using a Linux runner, such as Ubuntu, run can be used to issue the echo command to create a variable (foo in this example) with a value (Hello World in this example) and then redirect the output to $GITHUB_OUTPUT.

If you want to use the output in the same job, you would then use steps.<id>.outputs.<variable name> which would be steps.greeting.outputs.foo in this example.

name: GitHub Action (POC)
run-name: ${{ github.workflow }} run by ${{ github.actor }}
on:
  workflow_dispatch:
  
jobs:  
  poc:
    runs-on: ubuntu-latest
    steps:
      - name: echo Hello World
        id: greeting
        run: echo "foo=Hello World" >> $GITHUB_OUTPUT

      - name: echo foo
        run: |
          echo ${{ steps.greeting.outputs.foo }}

You can​ also

• Pass output between jobs
• Pass JSON output between jobs
• Pass input between workflows