script to automate aspects of spec URL updating (#3252)

scripts/find_unchanged_consensus_spec_files.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+PREV_VERSION=${1}
+NEXT_VERSION=${2}
+NIMBUS_SOURCE_DIR=${3}
+
+TMPDIR1=$(mktemp -d)
+TMPDIR2=$(mktemp -d)
+REPO_URL=https://github.com/ethereum/consensus-specs.git
+VALID=".*\\.\\(md\\|py\\)"
+UNCHANGED_SPEC_FILES=$(comm -12 --check-order <(git clone --branch "${PREV_VERSION}" --config advice.detachedHead=false --depth 1 --quiet "${REPO_URL}" "${TMPDIR1}" && cd "${TMPDIR1}" && find . -type f -regex "${VALID}" -print0 | xargs -0 sha256sum | sort) <(git clone --branch "${NEXT_VERSION}" --config advice.detachedHead=false --depth 1 --quiet "${REPO_URL}" "${TMPDIR2}" && cd "${TMPDIR2}" && find . -type f -regex "${VALID}" -print0 | xargs -0 sha256sum | sort) | awk '{print $2}' | sed -e"s/^\.\///" | shuf)
+
+# One can use this to automate the search andreplace with a tool such as
+# https://github.com/kcoyner/rpl/ or just a find/sed combination, e.g.,:
+URL_BASE=https://github.com/ethereum/consensus-specs/blob/
+FROM=${URL_BASE}${PREV_VERSION}/
+TO=${URL_BASE}${NEXT_VERSION}/
+echo "${UNCHANGED_SPEC_FILES}" | xargs -I{} printf "echo Replacing {}\nrpl --quiet --recursive -x.nim -x.md ${FROM}{} ${TO}{} ${NIMBUS_SOURCE_DIR} 2>/dev/null\n"
+
+# rpl's --quiet option does seem broken though.