joyrexus · December 16, 2015 03:19 · Apr 12, 2013 · Apr 12, 2013 · Apr 12, 2013
diff --git a/usage.md b/usage.md
@@ -1,7 +1,7 @@
 filter.coffee
 =============
 
-A sample coffee [filter](http://en.wikipedia.org/wiki/Filter_(Unix)).
+A sample coffee [filter](http://en.wikipedia.org/wiki/Filter_(Unix\)).
 
 ```
 $ echo "hi world" | filter.coffee

diff --git a/filter.coffee b/filter.coffee
@@ -1,15 +1,12 @@
-!/usr/bin/env coffee
-
+#!/usr/bin/env coffee
 fs = require 'fs'
-argv = require('optimist').argv
-print = console.log
 
-filter = (data) -> 
+transform = (data) -> 
   result = data.toString().replace /h/g, 'm'
-  print result
+  process.stdout.write result
 
-if argv._.length
-  filter fs.readFileSync(file, 'utf8') for file in argv._
+if process.argv.length > 2
+  transform fs.readFileSync(file, 'utf8') for file in process.argv[2..]
 else
-  process.stdin.on 'data', filter
-  process.stdin.resume()
+  process.stdin.on 'data', transform
+  process.stdin.resume()
diff --git a/usage.md b/usage.md
@@ -1,7 +1,7 @@
 filter.coffee
 =============
 
-A sample coffee filter.
+A sample coffee [filter](http://en.wikipedia.org/wiki/Filter_(Unix)).
 
 ```
 $ echo "hi world" | filter.coffee

diff --git a/filter.coffee b/filter.coffee
@@ -0,0 +1,15 @@
+!/usr/bin/env coffee
+
+fs = require 'fs'
+argv = require('optimist').argv
+print = console.log
+
+filter = (data) -> 
+  result = data.toString().replace /h/g, 'm'
+  print result
+
+if argv._.length
+  filter fs.readFileSync(file, 'utf8') for file in argv._
+else
+  process.stdin.on 'data', filter
+  process.stdin.resume()
diff --git a/usage.md b/usage.md
@@ -0,0 +1,17 @@
+filter.coffee
+=============
+
+A sample coffee filter.
+
+```
+$ echo "hi world" | filter.coffee
+mi world
+```
+
+```
+$ cat hello.txt
+hello world! 
+
+$ filter.coffee hello.text
+mello world!
+```