Add ShellCheck linter script

test/lint/lint-all.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2017-2019 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# This script runs all contrib/devtools/lint-* files, and fails if any exit
+# with a non-zero status code.
+
+# This script is intentionally locale dependent by not setting "export LC_ALL=C"
+# in order to allow for the executed lint scripts to opt in or opt out of locale
+# dependence themselves.
+
+set -u
+
+SCRIPTDIR=$(dirname "${BASH_SOURCE[0]}")
+LINTALL=$(basename "${BASH_SOURCE[0]}")
+
+EXIT_CODE=0
+
+for f in "${SCRIPTDIR}"/lint-*; do
+  if [ "$(basename "$f")" != "$LINTALL" ]; then
+    if ! "$f"; then
+      echo "^---- failure generated from $f"
+      EXIT_CODE=1
+    fi
+  fi
+done
+
+exit ${EXIT_CODE}

test/lint/lint-python.sh

@@ -13,7 +13,8 @@ elif flake8 --version | grep -q "Python 2"; then
 fi
 
 if [[ $# == 0 ]]; then
-    flake8 "$(git ls-files "*.py")" --extend-exclude "${EXCLUDE_PATTERNS}"
+    # shellcheck disable=SC2046
+    flake8 $(git ls-files "*.py") --extend-exclude "${EXCLUDE_PATTERNS}"
 else
     flake8 "$@"
 fi

test/lint/lint-shell.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2018-2021 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Check for shellcheck warnings in shell scripts.
+
+export LC_ALL=C
+
+# Disabled warnings:
+disabled=(
+)
+
+EXIT_CODE=0
+
+if ! command -v shellcheck > /dev/null; then
+    echo "Skipping shell linting since shellcheck is not installed."
+    exit $EXIT_CODE
+fi
+
+SHELLCHECK_CMD=(shellcheck --external-sources --check-sourced --source-path=SCRIPTDIR)
+EXCLUDE="--exclude=$(IFS=','; echo "${disabled[*]}")"
+# Check shellcheck directive used for sourced files
+mapfile -t SOURCED_FILES < <(git ls-files | xargs gawk '/^# shellcheck shell=/ {print FILENAME} {nextfile}')
+mapfile -t GUIX_FILES < <(git ls-files contrib/guix contrib/shell | xargs gawk '/^#!\/usr\/bin\/env bash/ {print FILENAME} {nextfile}')
+mapfile -t FILES < <(git ls-files -- '*.sh' | grep -vE 'src/(leveldb|secp256k1|minisketch|univalue)/')
+if ! "${SHELLCHECK_CMD[@]}" "$EXCLUDE" "${SOURCED_FILES[@]}" "${GUIX_FILES[@]}" "${FILES[@]}"; then
+    EXIT_CODE=1
+fi
+
+exit $EXIT_CODE