diff --git a/bin/dotenv.dart b/bin/dotenv.dart
index 0cb5ca4..29a76e9 100644
--- a/bin/dotenv.dart
+++ b/bin/dotenv.dart
@@ -1,9 +1,32 @@
 import 'dart:io';
 
+import 'package:args/args.dart';
 import 'package:dotenv/dotenv.dart' as dotenv;
 
+final _argPsr = new ArgParser()
+  ..addFlag('help', abbr: 'h', negatable: false, help: 'Print this help text.')
+  ..addOption('file',
+      abbr: 'f',
+      defaultsTo: '.env',
+      help: 'File to read.\nProvides environment variable definitions, one per line.');
+
 /// Prints the [env] map.
-void main() {
-  dotenv.load();
+///
+/// ## usage
+///
+///     pub global run dotenv --help
+void main(List<String> argv) {
+  var opts = _argPsr.parse(argv);
+
+  if (opts['help']) return _usage();
+
+  dotenv.load(opts['file']);
   stdout.writeln(dotenv.env);
 }
+
+void _usage() {
+  _p('Parse variable definitions from a file, print the environment and exit.');
+  _p('Usage: pub global run dotenv [-f <file>]\n${_argPsr.usage}');
+}
+
+void _p(String msg) => stdout.writeln(msg);
diff --git a/bin/new.dart b/bin/new.dart
index fea8486..78bf542 100644
--- a/bin/new.dart
+++ b/bin/new.dart
@@ -1,25 +1,40 @@
 import 'dart:io';
 
-const String envFile = '.env';
+import 'package:args/args.dart';
+
 const String gitignore = '.gitignore';
 
+final _argPsr = new ArgParser()
+  ..addFlag('help', abbr: 'h', negatable: false, help: 'Print this help text.')
+  ..addOption('file',
+      abbr: 'f',
+      defaultsTo: '.env',
+      help: 'File to create.\nDo not check secrets into version control!');
+
 /// Creates `.env` if the file does not exist, and adds it to `.gitignore`.
-void main() {
+///
+/// ## usage
+///
+///     pub global run dotenv:new --help
+void main(List<String> args) {
+  var opts = _argPsr.parse(args);
+
+  if (opts['help']) return _usage();
+
+  String envFile = opts['file'];
   _touch(envFile);
 
   var g = _touch(gitignore);
-  if (_anyLineContains(envFile, g)) return _handleError();
+  if (_anyLineContains(envFile, g)) return _handleIgnored(envFile);
 
-  g.writeAsStringSync('$envFile*\n', mode: FileMode.APPEND);
-  stdout.writeln('Added \'$envFile*\' to $gitignore.');
+  _appendTo(g, '$envFile*');
 }
 
 bool _anyLineContains(String str, File f) =>
     f.readAsLinesSync().any((line) => line.contains(str));
 
-void _handleError() {
-  stderr
-      .writeln('Found $gitignore with line containing \'$envFile\'; exiting.');
+void _handleIgnored(String filename) {
+  _pErr("Found $gitignore with line containing '$filename'; exiting.");
   exitCode = 1;
 }
 
@@ -31,3 +46,16 @@ File _touch(String filename) {
   stdout.writeln('Created file: $filename');
   return f;
 }
+
+void _appendTo(File f, String line) {
+  f.writeAsStringSync('$line\n', mode: FileMode.APPEND);
+  _p("Added '$line' to ${f.path}.");
+}
+
+void _usage() {
+  _p('Create a new file and gitignore it.');
+  _p('Usage: pub global run dotenv:new [-f <file>]\n${_argPsr.usage}');
+}
+
+void _p(String msg) => stdout.writeln(msg);
+void _pErr(String msg) => stderr.writeln(msg);
diff --git a/tool/fmt.sh b/tool/fmt.sh
index 852bc25..c541237 100755
--- a/tool/fmt.sh
+++ b/tool/fmt.sh
@@ -1,6 +1,5 @@
 #!/bin/sh
 
-# Add to `.git/hooks/pre-commit`:
-#   exec ./tool/fmt.sh
+# Autoformat code in-place, per style guidelines.
 
 dartfmt -w bin lib test example