[tpm] Filehandle $fh opened only for output at ....

[zoffix at zoffix.com]

Quoting Shlomi Fish <shlomif at shlomifish.org>:
> Hi Zoffix and Tom!

\o  Didn't expect you to follow Toronto's list :)

>>> As I recall the idiom is `while (defined(my $foo = <$fh>))`

I think I sidetracked the discussion with that comment :)

I highly doubt the `defined` is the cause of the issue or that perl  
would be lying about the handle not being opened for writing. Likely  
the handle is re-opened by some adjacent code or file handle's  
variable accidentally reused in another open, like passed via a sub,  
for example.

     $ perl -we 'open my $fh, "<", "foo"; open $fh, ">", "foo"; <$fh>'
     Filehandle $fh opened only for output at -e line 1.

     $ perl -we 'sub foo { open $_[0], ">", "foo"; }; open my $fh,  
"<", "foo"; foo $fh; <$fh>'
     Filehandle $fh opened only for output at -e line 1.

Perhaps the OP can provide a larger piece of code; something that  
traces the life of $fh.