--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/python/is_interactive.py	Mon Jun 24 16:06:24 2013 -0700
@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+
+"""
+illustrates usage of isatty
+
+Ref: http://www.tutorialspoint.com/python/file_isatty.htm
+"""
+
+import optparse
+import os
+import sys
+
+# DOES NOT WORK! :(
+# > echo 'foo' | is_interactive.py
+# Usage: is_interactive.py [options]
+
+# is_interactive.py: error: missing input
+
+
+def main(args=sys.argv[1:]):
+    parser = optparse.OptionParser()
+    options, args = parser.parse_args(args)
+
+    function = str.upper
+
+    if args:
+        # take input from command line args
+        input = ' '.join(args)
+    elif not sys.stderr.isatty():
+        # take input from stdin
+        input = sys.stdin.read()
+    else:
+        # no input! cry!
+        parser.error("missing input")
+
+    print function(input)
+
+if __name__ == '__main__':
+    main()