scripts: add mandoc_lint.sh

Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>

scripts/mandoc_lint.sh

@@ -0,0 +1,56 @@
+#!/bin/sh
+
+# Copyright (c) 2024 Manos Pitsidianakis <manos@pitsidianak.is>
+# Licensed under the EUPL-1.2-or-later.
+#
+# You may obtain a copy of the Licence at:
+# https://joinup.ec.europa.eu/software/page/eupl
+#
+# SPDX-License-Identifier: EUPL-1.2
+
+## shellcheck -o all -s sh -S style scripts/mandoc_lint.sh
+
+if test "$#" -ne 1; then
+  printf "Usage: %s PATH_TO_MANDOC_FILE\n" "${0}"
+  exit 1
+fi
+
+case "${1}" in
+-h)
+  printf "Usage: %s PATH_TO_MANDOC_FILE\n" "${0}"
+  exit 0
+  ;;
+--help)
+  printf "Usage: %s PATH_TO_MANDOC_FILE\n" "${0}"
+  exit 0
+  ;;
+*)
+  ;;
+esac
+
+if ! test -f "${1}"; then
+  printf "Argument %s either not exists or is not a regular text file.\n" "${1}"
+  exit 1
+fi
+
+section=$(echo "${1}" | rev | cut -d "." -f 1)
+
+tmpdir="$(mktemp --directory)"
+
+git show HEAD:"${1}" > "${tmpdir}/MANDOC_IN_HEAD.${section}"
+
+mandoc -T lint "${tmpdir}/MANDOC_IN_HEAD.${section}" 2> /dev/null | cut -d':' -f 5- > "${tmpdir}"/HEAD_LINT
+
+mandoc -T lint "${1}" 2> /dev/null | cut -d':' -f 5- > "${tmpdir}"/CHANGED_LINT
+
+diff -c "${tmpdir}"/HEAD_LINT "${tmpdir}"/CHANGED_LINT
+
+status=$?
+
+rm -rf "${tmpdir}"
+
+if test "${status}" -ne 0; then
+  printf "%s introduces new lint messages. Ignore if they are a false positive.\n" "${1}"
+fi
+
+# exit "${status}"