Added many, many more actions.

utils/envsubst/.github/workflows/test.yaml

@@ -0,0 +1,25 @@
+#This is an example of a possible way to Unit Test a single action.
+name: "Run unit tests."
+on: workflow_call
+jobs:
+  run-tests:
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@v3
+    - name: "Run Test"
+      id: test
+      uses: ./.
+      env:
+        TEST_VAR: Hello, world!
+      with:
+        input: |
+          And I say:
+          "$TEST_VAR"
+    - name: "Verify output."
+      uses: act/common/utils/compare@master
+      with:
+        expected: |
+          And I say:
+          "Hello, world!"
+        actual: |
+          ${{ steps.test.outputs.result }}

utils/envsubst/action.yaml

@@ -0,0 +1,31 @@
+name: envsubst
+description: "Substitute environment variables in the given input."
+inputs:
+  input:
+    description: "Input to substitute."
+    required: false
+  tmpDir:
+    description: "Temporary directory. Default: _tmp"
+    required: true
+    default: _tmp
+outputs:
+  result:
+    description: "The result of the substitution."
+    value: ${{ steps.envsubst.outputs.console }}
+runs:
+  using: "composite"
+  steps:
+  - name: "Make temporary file of input."
+    id: mktmp
+    uses: act/common/utils/mktemp@master
+    with:
+      input: ${{ inputs.input }}
+      tmpDir: ${{ inputs.tmpDir }}
+  - name: "Download file."
+    id: envsubst
+    uses: act/common/distros/rockylinux@master
+    with:
+      args: envsubst < ${{ steps.mktmp.outputs.tmp }}
+  - name: "Remove temporary files."
+    run: rm -rf "${{ inputs.tmpDir }}"
+    shell: bash