Add shell script linting with shellcheck for better portability

script/validate-shell-script.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+set -eu -o pipefail
+
+script_dir="$( cd "$( dirname "${0}" )" && pwd -P)"
+
+if command -v shellcheck
+then
+    # The list of shell script come from the (grep ...) command, feeding the loop
+    while IFS= read -r script_to_check
+    do
+        # The shellcheck command are run in background, to have an overview of the linter (instead of a fail at first issue)
+        shellcheck "${script_to_check}" &
+    done < <( # Search all the repository for sh and bash shebangs, excluding .js and .md files
+        # the folders ".git" and "vendor" are also ignored
+        grep -rI '#!/' "${script_dir}"/.. \
+        | grep 'sh' | grep -v '.js' | grep -v '.md' \
+        | grep -v '.git/' | grep -v 'vendor/' \
+        | cut -d':' -f1
+    )
+    wait # Wait for all background command to be completed
+else
+    echo "== Command shellcheck not found in your PATH. No shell script checked."
+fi