[perl #8063] perlfilter doesn't mention potential DATA clobber

Message-ID: <20030428150736.GD62281@geeknest.com>

p4raw-id: //depot/perl@19432

diff --git a/pod/perlfilter.pod b/pod/perlfilter.pod
index 0103f8c..51cd8ce 100644 (file)
--- a/pod/perlfilter.pod
+++ b/pod/perlfilter.pod
@@ -551,6 +551,20 @@ useful features from the C preprocessor and any other macro processors
 you know. The tricky bit will be choosing how much knowledge of Perl's
 syntax you want your filter to have.
 
+=head1 THINGS TO LOOK OUT FOR
+
+=over 5
+
+=item Some Filters Clobber the C<DATA> Handle
+
+Some source filters use the C<DATA> handle to read the calling program.
+When using these source filters you cannot rely on this handle, nor expect
+any particular kind of behavior when operating on it.  Filters based on
+Filter::Util::Call (and therefore Filter::Simple) do not alter the C<DATA>
+filehandle.
+
+=back
+
 =head1 REQUIREMENTS
 
 The Source Filters distribution is available on CPAN, in