add shellcheck script and workflow

Signed-off-by: Robert Marklund <[email protected]>

.github/workflows/shellcheck.yml

@@ -0,0 +1,22 @@
+name: run shellcheck on scripts
+
+on:
+  push:
+    branches:
+      - main
+      - devel
+  pull_request:
+
+
+jobs:
+  build:
+    name: Runs the shellcheck on scripts
+    runs-on: ubuntu-24.04
+
+    steps:
+   - name: checkout
+      uses: actions/checkout@v4
+    - name: install packages
+      run: sudo apt install shellcheck
+    - name: run shellcheck
+      run: ./do_shellcheck.sh

do_shellcheck.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+set -e
+
+me=$(basename "$0")
+
+
+echo "$me: run shellcheck on shellscripts"
+(
+    # use this when all issues are fixed
+    # git ls-files | grep -v "^testcases" | grep -E ".sh$" | xargs shellcheck
+    shellcheck do_shellcheck.sh
+)
+
+echo "$me: run shellcheck on testcases"
+(
+    # use this when all issues are fixed
+    # cd testcases && git ls-files | grep -E ".sh$" | xargs shellcheck -x
+    cd testcases && shellcheck -x ./checksum_buffersize*.sh
+)
+