Only wait for stdin for a little bit

For this module, we only really care about stdin that is written right away, like when the process is piped.

This has the benefit of letting us easily add a fallback when there's no stdin.

Fixes #13

index.js

@@ -10,9 +10,17 @@ module.exports = () => {
 			return;
 		}
 
+		const timeout = setTimeout(() => {
+			resolve(ret);
+		}, 100);
+
+		stdin.unref();
 		stdin.setEncoding('utf8');
 
 		stdin.on('readable', () => {
+			clearTimeout(timeout);
+			stdin.ref();
+
 			let chunk;
 
 			while ((chunk = stdin.read())) {
@@ -36,7 +44,16 @@ module.exports.buffer = () => {
 			return;
 		}
 
+		const timeout = setTimeout(() => {
+			resolve(new Buffer(''));
+		}, 100);
+
+		stdin.unref();
+
 		stdin.on('readable', () => {
+			clearTimeout(timeout);
+			stdin.ref();
+
 			let chunk;
 
 			while ((chunk = stdin.read())) {

readme.md

@@ -2,6 +2,8 @@
 
 > Get [stdin](https://nodejs.org/api/process.html#process_process_stdin) as a string or buffer
 
+This module expects stdin to be written right away. It's not intended for stdin being written at some arbitrary time.
+
 
 ## Install
 
@@ -16,21 +18,26 @@ $ npm install --save get-stdin
 // example.js
 const getStdin = require('get-stdin');
 
-getStdin().then(str => {
-	console.log(str);
-	//=> 'unicorns'
+getStdin().then(stdin => {
+	if (stdin.length > 0) {
+		console.log('stdin:', str);
+	} else {
+		console.log('input:', process.argv[2]);
+	}
 });
 ```
 
 ```
 $ echo unicorns | node example.js
-unicorns
+stdin: unicorns
+$ node example.js unicorns
+input: unicorns
 ```
 
 
 ## API
 
-Both methods returns a promise that is resolved when the `end` event fires on the `stdin` stream, indicating that there is no more data to be read.
+Both methods returns a promise that is resolved when the `end` event fires on the `stdin` stream or after 100ms, indicating that there is no more data to be read.
 
 ### getStdin()