bird2code.awk

# bird2code.awk
/^[^>]/ || /^$/ {print; next}

/^>/ {
  print "\\begin{code}"
  sub(/^> ?/,"")
  print
  rc = getline
  while(($0 ~ /^>/) && (rc > 0)) {
    sub(/^> ?/,"")
    print
    rc = getline
  }
  print "\\end{code}\n"
}