[BUILD] add code style check for shell scripts
diff --git a/.github/workflows/shfmt.yml b/.github/workflows/shfmt.yml
new file mode 100644
index 0000000..8e474fd
--- /dev/null
+++ b/.github/workflows/shfmt.yml
@@ -0,0 +1,49 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+name: "shfmt: shell script code style"
+
+on:
+ push:
+ pull_request:
+
+jobs:
+ shfmt:
+ name: shfmt
+ runs-on: ubuntu-latest
+ env:
+ SHFMT_VERSION: '3.6.0'
+ # --indent 2: 2 spaces of indentation
+ # --case-indent: switch cases will be indented
+ # --diff: error with a diff when the formatting differs
+ SHFMT_OPTS: '--indent 2 --case-indent --diff'
+ steps:
+ - uses: actions/checkout@v3
+
+ - name: download
+ shell: bash
+ run: |
+ mkdir -p "$HOME/.local/apps/shfmt_v${SHFMT_VERSION}_linux_amd64"
+ curl --silent --fail --show-error --retry 2 --retry-delay 1 --connect-timeout 5 --location --url "https://github.com/mvdan/sh/releases/download/v${SHFMT_VERSION}/shfmt_v${SHFMT_VERSION}_linux_amd64" -o "$HOME/.local/apps/shfmt_v${SHFMT_VERSION}_linux_amd64/shfmt"
+ chmod +x "$HOME/.local/apps/shfmt_v${SHFMT_VERSION}_linux_amd64/shfmt"
+ echo "$HOME/.local/apps/shfmt_v${SHFMT_VERSION}_linux_amd64" >> $GITHUB_PATH
+
+ - name: check
+ shell: bash
+ run: |
+ readarray -t SCRIPT_FILES < <(shfmt -f "$GITHUB_WORKSPACE/maven-wrapper-distribution/src/resources")
+ shfmt ${SHFMT_OPTS} "${SCRIPT_FILES[@]}"
