I get "Use of uninitialized value in open" the second time through the
loop.  However, if I declare $buff before the loop (and not in the
loop), I don't get the error.

Can someone explain what is happening?

use strict;
use warnings;

$| = 1;
#my $buff;

foreach (1..2) {
    print "starting iteration $_\n";
    my $buff;
    open(my $TMPBUF,'>',\$buff) || die "open, $!\n";
    print {$TMPBUF} "$_\n";
    close($TMPBUF);

#   print "buff=>$buff<\n";
}

Output::
starting iteration 1
starting iteration 2
Use of uninitialized value in open at j.pl line 10.

On 2011-04-05 22:27, Mark <google@markginsburg.com> wrote:
> I get "Use of uninitialized value in open" the second time through the
> loop.  However, if I declare $buff before the loop (and not in the
> loop), I don't get the error.
>
> Can someone explain what is happening?
[...]
> foreach (1..2) {
>     print "starting iteration $_\n";
>     my $buff;
>     open(my $TMPBUF,'>',\$buff) || die "open, $!\n";
[...]
> }
>
> Output::
> starting iteration 1
> starting iteration 2
> Use of uninitialized value in open at j.pl line 10.

I get this warning with perl 5.8.8 but not with 5.10.1, so I guess it's
a bug which was fixed in perl 5.10. 

As a workaround you can just assign an empty string to $buff:

    my $buff = "";

    	hp

Peter J. Holzer <hjp-usenet2@hjp.at> wrote:
> On 2011-04-05 22:27, Mark <google@markginsburg.com> wrote:
>> I get "Use of uninitialized value in open" the second time through the
>> loop.  However, if I declare $buff before the loop (and not in the
>> loop), I don't get the error.
>>
>> Can someone explain what is happening?
> [...]
>> foreach (1..2) {
>>     print "starting iteration $_\n";
>>     my $buff;
>>     open(my $TMPBUF,'>',\$buff) || die "open, $!\n";
> [...]
>> }
>>
>> Output::
>> starting iteration 1
>> starting iteration 2
>> Use of uninitialized value in open at j.pl line 10.
>
> I get this warning with perl 5.8.8 but not with 5.10.1, so I guess it's
> a bug which was fixed in perl 5.10. 


I get it with 5.10.0, so it must have been 5.10.1 that fixed it...


-- 
Tad McClellan
email: perl -le "print scalar reverse qq/moc.liamg\100cm.j.dat/"
The above message is a Usenet post.
I don't recall having given anyone permission to use it on a Web site.