Help in rotate 13 program

[Chris Angelico]

On Thu, Dec 29, 2011 at 10:48 PM, Sayantan Datta <kenzo.zombie at gmail.com> wrote:
>     for line in sys.stdin :
>       for char in line :
> sys.stdout.write(rotate13_letter(char))
>
> cat sample.html | python rot13.py rot13.html

You're reading from stdin, which is correct, but you're writing to
stdout and not redirecting it. You need to put an arrow before
rot13.html to indicate redirection:

cat sample.html | python rot13.py >rot13.html

Note though that 'cat' is superfluous here; all you need to do is
redirect input:
python rot13.py <sample.html >rot13.html

Hope that helps!

Chris Angelico