Re: use strict and filehandles

[B McKee]

On Tuesday, January 20, 2004, at 10:34  AM, B McKee wrote:

Hi All,
I'm having trouble understanding what use strict is trying to tell me.
If I have run this program
...snipped
open(MESSAGE, "$datafile") or die "Cannot open datafile: $!";
while (!eof(MESSAGE)) {
    $page = new CGI(MESSAGE);
...more snippage
I get this
-RESULTS------------------------------------------
Bareword "MESSAGE" not allowed while "strict subs" in use at 
./errorprog.pl
        line 16 (#1)
    (F) With "strict subs" in use, a bareword is only allowed as a
    subroutine identifier, in curly brackets or to the left of the 
"=>" symbol.
    Perhaps you need to predeclare a subroutine?
...more snippage
My questions are:
1)  Why is it warning me at all?  Using a bare word in the filehandle 
is common
in my Perl manuals.  In this case a bare word does everything I need 
it to do.
What is this warning trying to prevent?
2)  If I replace MESSAGE with $filehandlename and add $filehandlename 
to the my () block
it doesn't complain.  If I do that I haven't assigned a value to 
$filehandlename.
Does that mean my filehandle is actually 'undef'?
That doesn't seem right somehow, especially if I have multiple files 
open in
a different circumstance.  What value should I assign to 
$filehandlename? MESSAGE?
Yep, I'm replying to my own post.

I have now also determined that quoting the word 'MESSAGE' above
e.g. open('MESSAGE', "$datafile")
clears the error.  I guess use strict is trying to make sure I
didn't actually mean to use some sort of variable.
This is how I think I'll proceed in this case.  I don't need to ever
change the value of the filehandle in this subroutine.
  -->side note:  I gather the "" around $datafile are kinda pointless 
too.....
Brian

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