Each lab will consist of a small problem and details of how to proceed. Each lab is intended to give every student hands-on experience with the core concepts and technologies covered during the course.  A student may concentrate, as a team member, on one technology over another for the final project, but labs are designed to give each and every student exposure to all the technologies that come into play.  You need to submit labs to the TAs for grading--see submission instructions below.  Generally, unless otherwise specified, you will have one week to complete each assigned lab.

See the syllabus for information on grading.  Turning in lab assignments on time is required, without exception, and all late deliveries will be penalized, regardless of cause.  Submit your assignments to the subversion repository according to the directions on the syllabus page.

You may write these solutions in any programming language of your choice.  Our suggestion is now is not the time to learn a new programming language along with the concepts themselves.  So our suggestion is to use whatever programming language you  know best.

Lab 1   Due: 5:00 pm, Monday, April 8, 2019

System Setup and Software Installation: 

BACKGROUND:

STEP 1:  Installing Bitcoin Core

Go to https://bitcoincore.org/en/download/ and download the version 0.17.1 of the software for the mac.   Make sure you download the tar.gz file, as in here:



After downloading, you will have a new tar file called

$ which bitcoin-qt

You see:

/usr/local/Bitcoin/bin/bitcoin-qt

Now, run it:

$ bitcoin-qt

You will see a warning dialog saying that it will install under (again this is the Mac) ~/Library/Application Support/Bitcoin, and it will also warn you that you're going to need some 280 GIGABYTES of free space, of which you will perhaps have less than that, possibly much less.  NO WORRIES.  We're not going to actually download the entire Bitcoin Mainnet.  We're just going to let it think it's doing that...let it get itself started.

Once you click on Continue, you'll see that it starts "Syncing Headers" in the lower left status bar.  The picture below shows headers at 81.4% complete.  Let it get to 100%. 



Once you've got all the headers, it will begin to actually download the bitcoin blockchain.  Again, don't panic if you only have 20 gig free.  We're not going to let it get close to that. 

You'll see that it starts downloading blocks in the blockchain, and that will look like this:



In this image, you can see that it's begun "Synchronizing with network..." (see status bar lower left).  This is a GOOD SIGN.  You're downloading the Bitcoin blockchain.  But to you really want to spend "3 weeks" downloading the whole enchilada?  This screen shows there's over half a million blocks still to download.  Once you see that the blocks are successfully downloading, you can click on File/Close to exit out of bitcoin-qt.  This will be that last time we run this in our labs. 

WHERE ARE WE?  We have successfully installed the bitcoin core software, and we have initialized our environment and software.  Now, let's look in that Bitcoin directory:

export BLOCKCHAIN='testnet'
export BX_CONFIG=/usr/local/etc/libbitcoin/bx.testnet.cfg
alias btcdir="cd ~/.bitcoin/" #linux default bitcoind path
alias bitc='/usr/local/Bitcoin/bin/bitcoin-cli -${BLOCKCHAIN}'
alias bitd='/usr/local/Bitcoin/bin/bitcoind -${BLOCKCHAIN} -printtoconsole'
alias bitd-MAINNET='/usr/local/Bitcoin/bin/bitcoind -conf=bitcoin.MAINNET.conf -printtoconsole'
alias bitc-MAINNET='/usr/local/Bitcoin/bin/bitcoin-cli -conf=bitcoin.MAINNET.conf'
alias btcinfo='bitcoin-cli -${BLOCKCHAIN} getwalletinfo | egrep "\"balance\""; bitcoin-cli -${BLOCKCHAIN} getnetworkinfo | egrep "\"version\"|connections"; bitcoin-cli -${BLOCKCHAIN} getmininginfo | egrep "\"blocks\"|errors"'
alias      btcblockjson="echo \`wget --no-check-certificate -O - https://testnet.blockexplorer.com/api/status?q=getBlockCount 2> /dev/null\`"
alias     btcblocksofar='echo `bitcoin-cli -testnet getblockcount 2>&1`'
alias     btcblocktotal='echo `btcblockjson` | sed "s/.*blocks.:\([0-9]*\).*/\1/"'
alias          btcblock='echo `btcblocksofar`/`btcblocktotal`'
alias btcinfo-MAINNET='bitcoin-cli -conf=bitcoin.MAINNET.conf getwalletinfo | egrep "\"balance\""; bitcoin-cli -${BLOCKCHAIN} getnetworkinfo | egrep "\"version\"|connections"; bitcoin-cli -${BLOCKCHAIN} getmininginfo | egrep "\"blocks\"|errors"'
alias btcblock-MAINNET='echo `bitcoin-cli -conf=bitcoin.MAINNET.conf getblockcount 2>&1`/`wget -O - https://blockexplorer.com/api/status?q=getBlockCount 2> /dev/null | cut -d : -f2 | rev | cut -c 2- | rev`'
			

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