--- subprocess.py.273	2012-12-05 17:44:45.970021863 -0500
+++ subprocess.py	2012-12-05 17:53:01.878331857 -0500
@@ -138,6 +138,9 @@ check_output(*popenargs, **kwargs):
 
     output = check_output(["ls", "-l", "/dev/null"])
 
+    There is an additional optional argument, "input", allowing you to
+    pass a string to the subprocess's stdin.  If you use this argument
+    you may not also use the Popen constructor's "stdin" argument.
 
 Exceptions
 ----------
@@ -531,11 +534,29 @@ def check_output(*popenargs, **kwargs):
     ...               "ls -l non_existent_file ; exit 0"],
     ...              stderr=STDOUT)
     'ls: non_existent_file: No such file or directory\n'
+
+    There is an additional optional argument, "input", allowing you to
+    pass a string to the subprocess's stdin.  If you use this argument
+    you may not also use the Popen constructor's "stdin" argument, as
+    it too will be used internally.  Example:
+
+    >>> check_output(["sed", "-e", "s/foo/bar/"],
+    ...              input="when in the course of fooman events\n")
+    'when in the course of barman events\n'
+
     """
     if 'stdout' in kwargs:
         raise ValueError('stdout argument not allowed, it will be overridden.')
+    if 'input' in kwargs:
+        if 'stdin' in kwargs:
+            raise ValueError('stdin and input arguments may not be used together.')
+        inputdata = kwargs['input']
+        del kwargs['input']
+        kwargs['stdin'] = PIPE
+    else:
+        inputdata = None
     process = Popen(stdout=PIPE, *popenargs, **kwargs)
-    output, unused_err = process.communicate()
+    output, unused_err = process.communicate(inputdata)
     retcode = process.poll()
     if retcode:
         cmd = kwargs.get("args")