scripts/extract_keylines.sh

#!/usr/bin/env bash
# Extract KEYLINEs from one or more log files.
# Usage: scripts/extract_keylines.sh /path/to/log1.log [/path/to/log2.log ...]
set -u

if [ $# -lt 1 ]; then
  echo "usage: $0 <logfile...>" >&2
  exit 2
fi

for f in "$@"; do
  echo "=== $f ==="
  grep '^KEYLINE ' "$f" || true
  echo
done