diff --git a/bin/cli.js b/bin/cli.js
new file mode 100644
index 0000000..033bf36
--- /dev/null
+++ b/bin/cli.js
@@ -0,0 +1,24 @@
+(function () {
+'use strict';
+
+var hexdump = require('../').hexdump;
+var fsname = process.argv[2];
+var fs = require('fs');
+
+if (!fsname || '--help' === fs || '-h' === fs) {
+  console.error('Usage: hexdump.js <filepath>');
+  return;
+}
+
+try {
+  fs.statSync(fsname);
+} catch(e) {
+  console.error(e.message);
+  return;
+}
+
+var nb = fs.readFileSync(fsname);
+var str = hexdump(nb.buffer, nb.byteOffset, nb.byteLength);
+console.log(str);
+
+}());
diff --git a/hexdump.js b/hexdump.js
index 34e2486..918a880 100644
--- a/hexdump.js
+++ b/hexdump.js
@@ -1,8 +1,8 @@
 (function (exports) {
 'use strict';
 
-exports.hexdump = function hexdump(ab) {
-  var ui8 = new Uint8Array(ab);
+exports.hexdump = function hexdump(ab, offset, len) {
+  var ui8 = new Uint8Array(ab.buffer || ab, offset || ab.byteOffset, len || ab.byteLength);
   var bytecount = 0;
   var head = '        0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F';
   var trail;
@@ -22,7 +22,8 @@ exports.hexdump = function hexdump(ab) {
 
     return lead + ' ' + str;
   }).join('\n');
-  trail = ab.byteLength.toString(16);
+
+  trail = (len || ab.byteLength).toString(16);
   while (trail.length < 7) {
     trail = '0' + trail;
   }
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..c47ca93
--- /dev/null
+++ b/package.json
@@ -0,0 +1,21 @@
+{
+  "name": "hexdump",
+  "version": "1.0.0",
+  "description": "Like hexdump on *nix, but in JavaScript.",
+  "main": "hexdump.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git@git.daplie.com:Daplie/hexdump.js.git"
+  },
+  "keywords": [
+    "hexdump",
+    "binary",
+    "bin",
+    "js"
+  ],
+  "author": "AJ ONeal <coolaj86@gmail.com> (https://coolaj86.com)",
+  "license": "MIT"
+}