Export difficulty adjustments in testnet from BTC testnet node

export_testnet_difficulty_adjustments.sh

#!/bin/bash

# Description:
# Analyze testnet difficulty changes.
# This script iterates over the blocks and exports blockheight, time, mediantime,
# difficulty, bits and blockhash for all blocks around difficulty adjustments
# (5 blocks before and 5 blocks afterwards).
#
# Author: John Zweng,30.04.2024


###############################################################################
## config:
###############################################################################
start_block=2570390  # some block from January 2024, before the block storm
end_block=2808470    # chaintip at time of creating this script
##
csv_file="testnet_difficulty_adjustments_2024.csv"
###############################################################################
###############################################################################

# write csv header
echo "height,time,mediantime,difficulty,bits,blockhash,blknum_in_diff_period" >> $csv_file

counter=0

# Loop through the specified range of block numbers
for (( block=$start_block; block<=$end_block; block++ ))
do
        # index of current block within difficulty period (starts with 0, up to 2015)
        block_in_diff_period=$((block % 2016))

        # we are only interested in the blocks around difficulty adjustment
        if (( block_in_diff_period > 2010   ||   block_in_diff_period < 5 )); then

                # just a gimmick, repeat header in terminal every 20 lines (not in CSV)
                if (( counter % 20 == 0 )); then
                        echo "height,time,mediantime,difficulty,bits,blockhash,blknum_in_diff_period"
                fi

                # Fetch the block hash for the current block number
                blockhash=$(bitcoin-cli getblockhash $block)

                header_csv=$(bitcoin-cli getblockheader $blockhash | jq -r '[.height, .time, .mediantime, .difficulty, .bits, .hash] | @csv')
                echo $header_csv,$block_in_diff_period

                # write ino csv file
                echo $header_csv,$block_in_diff_period  >> $csv_file

                # Increment the counter
                ((counter++))

        fi

done
echo "Finished. :)"