in reply to Why no stay shared warning?

The normal idiom for a "static local" variable is to declare it inside a BEGIN block, and put the acccessor subroutines within that same block. Just add BEGIN to your block, and you're done! 
up(); 
up(); 
print get(); 
BEGIN { 
my $foo = 1; 
sub up { 
        $foo++; 
sub get {$foo} 
} 
}

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This is needed because you need the block executed once in order for the variable to go into and then out of scope, forming a closure with your two named subroutines.

-- Randal L. Schwartz, Perl hacker

Replies are listed 'Best First'.
Re: Re: Why no stay shared warning?
by danger (Priest) on May 05, 2001 at 21:48 UTC

    Note, a BEGIN block isn't necessary -- a bare block is fine as long as it is defined prior to the sub calls. Also, a BEGIN block may not always be the appropriate mechanism: 

    #!/usr/bin/perl -w
use strict;
use Getopt::Std;

my %opt;
getopt('n',\%opt);

BEGIN
{ 
  my $foo = $opt{n};
  sub up { 
    $foo++; 
    sub get {$foo} 
  } 
}

up(); 
up(); 
print get();

    [download]

    Now, if you comment out the BEGIN line above it will work as one might have expected. Not that I think this might be a common problem, but I thought it might be worthwhile to highlight the difference.

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[d/l]

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