diff --git a/index.js b/lib/index.js
similarity index 71%
rename from index.js
rename to lib/index.js
index d17b84d..246c6f8 100644
--- a/index.js
+++ b/lib/index.js
@@ -2,11 +2,13 @@
 
 const stream = require('stream');
 const EventEmitter = require('events').EventEmitter;
-const pkg = require('./package.json');
+const pkg = require('../package.json');
 let lib = require('bindings')('vcd.node');
 
 module.exports = () => {
 
+  const triggers = [];
+
   const info = {path: []};
 
   const s = new stream.Writable();
@@ -24,9 +26,13 @@ module.exports = () => {
     callback();
   };
 
-  s.onTrigger = (id, fn) => {
-    lib.setTrigger(cxt, id);
-    triee.on(id, fn);
+  s.change = {
+    on: (id, fn) => {
+      triggers.push(id);
+      const triggerString = triggers.join(' ') + '  ';
+      lib.setTrigger(cxt, triggerString);
+      triee.on(id, fn);
+    }
   };
 
   s.version = pkg.version;
diff --git a/package.json b/package.json
index 45a1960..b248109 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "description": "Value Change Dump (VCD) parser",
   "main": "lib/index.js",
   "scripts": {
-    "test": "eslint bin && nyc -r=text -r=lcov mocha",
+    "test": "eslint bin lib && nyc -r=text -r=lcov mocha",
     "build": "node bin/build.js && node-gyp rebuild"
   },
   "repository": {
diff --git a/test/basic.js b/test/basic.js
index 7bda9b4..469979a 100644
--- a/test/basic.js
+++ b/test/basic.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const expect = require('chai').expect;
-const vcd = require('../index.js');
+const vcd = require('../lib/index.js');
 
 describe('basic', () => {
 
diff --git a/vcd.c b/vcd.c
index c636b4a..aa67179 100644
--- a/vcd.c
+++ b/vcd.c
@@ -55,7 +55,7 @@
       return 0; \
     } \
     size_t result; \
-    if (napi_get_value_string_latin1(env, tmp, var, 256, &result) != napi_ok) { \
+    if (napi_get_value_string_latin1(env, tmp, var, 4096, &result) != napi_ok) { \
       napi_throw(env, name); \
       return 0; \
     } \
@@ -122,7 +122,7 @@ METHOD(init) {
   ASSERT_FUNCTION(args[1], state->triee)
   ASSERT_OBJECT(args[2], state->hier)
 
-  static char triggerString [256];
+  static char triggerString [4096] = "       ";
 
   state->trigger = triggerString;
   state->reason = "NO REASON";
diff --git a/vcd_spans.c b/vcd_spans.c
index 8aa7e47..0c63542 100644
--- a/vcd_spans.c
+++ b/vcd_spans.c
@@ -9,19 +9,31 @@
     }
 
 int stringEq (
-  const unsigned char* gold,
+  const unsigned char* gold, // search pattern
   const unsigned char* p,
   const unsigned char* endp
 ) {
-  if (gold[0] == 0) {
-    return 0;
-  }
-  for (size_t i = 0; gold[i] != 0; i++) {
-    if (gold[i] != p[i]) {
+  unsigned char* i;
+  unsigned char* j;
+  i = gold;
+  j = p;
+  while (1) {
+    if (*i == ' ') { // end of search pattern
       return 0;
     }
+    while (*i == *j) { // follow matching trail
+      i++;
+      j++;
+    }
+    if ((*i == ' ') && (j == (endp - 1))) { // exact match
+      return 1;
+    }
+    while (*i != ' ') { // skip to the end of pattern word
+      i++;
+    }
+    i++;
+    j = p; // try another word
   }
-  return 1;
 }
 
 int commandSpan(vcd_parser_t* state, const unsigned char* p, const unsigned char* endp) {