block_stats.sh

#!/usr/bin/env zsh

# NOTE:
#   Running this script requires:
#    * bitcoind - full archival node,
#    * jq - `sudo apt install jq`,
#    * zsh - `sudo apt install zsh`.

FILE=~/block_data.txt
MAX=$(bitcoin-cli getblockcount)
STEP=100

COUNTER=0
if [ -f "${FILE}" ]; then
  COUNTER=$(tail -n 1 "${FILE}" | cut -d ' ' -f 2)
fi

if [ "${MAX}" != "${COUNTER}" ]; then
  COUNTER=$(expr ${COUNTER} + 1)
  echo "Fetching block timestamps starting from ${COUNTER}…"

  batch=""

  until [ ${COUNTER} -ge ${MAX} ]; do
    batch="${batch}$(bitcoin-cli getblockheader $(bitcoin-cli getblockhash ${COUNTER}) | jq '.time') ${COUNTER}\n"
    if [ $(expr ${COUNTER} % ${STEP}) -eq 0 ]; then
      echo -n "${batch}" >> ${FILE}
      echo "Blocks $(expr ${COUNTER} - ${STEP} + 1) to ${COUNTER} processed"
      batch=""
    fi

    COUNTER=$(expr ${COUNTER} + 1)
  done

  if [ ! -z "${batch}" ]; then
    echo -n "${batch}" >> ${FILE}
  fi

  echo "Fetching timestamps done"
else
  echo "Block timestamps are up-to-date"
fi

# make sure there's no gaps in block data
gaps="$(awk 'NR==1{p=$2;next}{print $2-p; p=$2}END{}' block_data.txt | sort | uniq | wc -l)"
if [ ${gaps} != 1 ]; then
  echo "Some blocks are missing!"
  exit 1

else
  echo "No gaps in the set"
fi

# calculate time difference between each two concurrent blocks
echo -n "Calculating differences… "
awk 'NR==1{p=$1;next}{print $1-p; p=$1}END{}' block_data.txt > block_diffs.txt
echo "done"

# sort all differences
echo -n "Sorting differences… "
cat block_diffs.txt | sort -n > block_diffs_sorted.txt
echo "done"

BOLD=$(tput bold)
RESET_STYLE=$(tput sgr0)

# calculate median time between blocks
echo -n "Calculating median time between blocks… "
median="$(awk '{count[NR]=$1;}END{if(NR%2){print count[(NR+1)/2];}else{print (count[(NR/2)] + count[(NR/2)+1])/2.0;}}' block_diffs_sorted.txt)"
echo "done: ${BOLD}$(expr ${median} / 60)m $(expr ${median} % 60)s${RESET_STYLE}"

# calculate average time between blocks
echo -n "Calculating average time between blocks… "
average="$(awk '{total+=$1;count++}END{print int(total/count)}' block_diffs_sorted.txt)"
echo "done: ${BOLD}$(expr ${average} / 60)m $(expr ${average} % 60)s${RESET_STYLE}"