Adding script to print events logged to the blockchain

bin/events.js

+#!/usr/bin/node
+// 20200828 Robert Martin-Legene
+// License: GPLv2-only
+// (c) Secretaria Legal y Tecnica, Presidencia De La Nacion, Argentina
+
+// Looks for the contract you're specifying as argument.
+// Tries to show you all the events that contract has ever logged on the blockchain.
+// The contract's ABI must be in a text file in ${BFANETWORKDIR}/contracts/${contractaddr}/abi
+
+const Web3		= require( "web3" );
+const fs		= require( "fs" );
+const web3		= new Web3( "http://127.0.0.1:8545" );
+
+function writeEvent(ev)
+{
+	console.log("");
+	console.log( "Block number: " + ev.blockNumber );
+	console.log( "TX hash: "      + ev.transactionHash );
+	console.log( "Event name: "   + ev.event );
+	Object.keys( ev.returnValues ).forEach(
+		function writeEventValue( value )
+		{
+			// Will skip keys which are made entirely of digits.
+			if ( ! value.match(/^[0-9]+$/) )
+			{
+				console.log( "* " + value + ": " + ev.returnValues[value] )
+			}
+		}
+	);
+}
+
+
+function gotPastEvents( e, result )
+{
+	// We are called a single time.
+	// Either success or failure.
+	if ( e )
+	{
+		console.error( e );
+		process.exit( 1 );
+	}
+	result.forEach( writeEvent );
+	console.log( "\n" + result.length + " events." );
+}
+
+var	contractname	=	process.argv[2];
+if ( contractname === undefined )
+{
+        console.error( "Usage: " + process.argv[1] + " <contractname|contractaddr>" );
+        process.exit( 1 );
+}
+if ( process.env.BFANETWORKDIR === undefined ) 
+{
+	console.error( "$BFANETWORKDIR must be defined" );
+	process.exit( 1 );
+}
+var	pathprefix	=	process.env.BFANETWORKDIR + "/contracts/";
+var	filename;
+if ( fs.existsSync( 		contractname ))
+	filename	=	contractname;
+else
+if ( fs.existsSync( 		contractname.toLowerCase() ))
+	filename	=	contractname.toLowerCase();
+else
+if ( fs.existsSync( 		pathprefix + contractname ))
+	filename	=	pathprefix + contractname;
+else
+if ( fs.existsSync( 		pathprefix + contractname.toLowerCase() ))
+	filename	=	pathprefix + contractname.toLowerCase();
+if ( filename === undefined )
+{
+	console.error( "Contract not found." );
+	process.exit( 1 );
+}
+var	contractaddr	=	filename;
+var	dirname		=	"";
+var	idx		=	filename.lastIndexOf("/");
+if ( idx > -1 )
+{
+	dirname		=	filename.substr( 0, idx+1 );
+	filename	=	filename.substr( idx+1    )
+	contractaddr	=	filename;
+}
+var	stats		=	fs.lstatSync( dirname + filename );
+if ( stats.isSymbolicLink() )
+{
+	let linkname	=	fs.readlinkSync( dirname + filename, { encoding: 'utf8' } );
+	filename	=	dirname + linkname;
+	contractaddr	=	linkname;
+}
+filename		+=	"/abi";
+var	abi_str		=	fs.readFileSync( filename, { encoding: 'utf8' } );
+var	abi		=	JSON.parse( abi_str );
+var	contract	=	new web3.eth.Contract( abi, contractaddr );
+console.log( "Address: "      + contractaddr );
+contract.getPastEvents( "allEvents", { fromBlock: "earliest", toBlock: "latest" }, gotPastEvents);