Added keccak256.js to get signatures

package.json

@@ -74,6 +74,8 @@
     }
   },
   "dependencies": {
+    "keccak": "^3.0.1",
+    "keccak256": "^1.0.3",
     "phantomjs-prebuilt": "^2.1.16",
     "sol2uml": "^1.1.17",
     "yarn": "^1.22.10"

scripts/keccak256.js

@@ -0,0 +1,23 @@
+// This is a nodejs script to compute the selectors of Solidity events or functions
+// (four bytes of the Keccak-256 or SHA-3 hash of the signature of the function)
+// Install: npm i keccak256
+
+var myArgs = process.argv.slice(2);
+// console.log('arg: ', String(myArgs[0]).split(/\r?\n/));
+
+let signatures = String(myArgs[0])
+    .replace(/;/g, '') // remove final ;
+    .split(/\r?\n/) // split lines, every line is a signature
+    .sort(function(a, b){ // sorted alphabetically
+        if(a < b) { return -1; }
+        if(a > b) { return 1; }
+        return 0;
+    })
+    .filter((item, i, ar) => ar.indexOf(item) === i) // get unique
+;
+// console.log('signatures: ', signatures);
+
+const keccak256 = require('keccak256');
+for(let s of signatures) {
+    if (s) console.log(s + "\t" + "0x" + keccak256(s).toString('hex'));
+}