in reply to Re: setting PERL_PERTURB_KEYS & PERL_HASH_SEED in a perl file
in thread setting PERL_PERTURB_KEYS & PERL_HASH_SEED in a perl file

Ah, thank you fellow monks for the insight. (actually, I tried tye's way, but it did not work then) Thus:

BEGIN{
    unless (defined $ENV{APPLEJACK}){
      $ENV{APPLEJACK}= "TRUEBLUE";
      exec( $^X, $0, @ARGV );
      exit 0; # we actually never get here
    }
}

print "STARTING " . $ENV{APPLEJACK} . "\n";

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prints:

STARTING TRUEBLUE

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Re^3: setting PERL_PERTURB_KEYS & PERL_HASH_SEED in a perl file
by gravid (Novice) on Jul 18, 2016 at 12:51 UTC

    Thx Everyone.

    The solution you gave indeed work.

    exec( $^X, $0, @ARGV );

    I was sure that whatever written inside a BEGIN statement is hapannig before everything else, so I'm not sure why my first attempt did't wok

    Isn't there a way to solve that without recalling the script again?

    By the way, I don't rely on hash to be sorted, but in this case I did my sort base on the values and not the keys.

    Since the values might be equal I got inconsistent printing while in earlier perl version the printing was consistent.

    Thx

    Guy

[reply]

      Hi gravid,

      Could you show a short example of the kind of sort you're doing (some sample input data, brief code and expected output)? I'm almost certain there's a better solution than messing with Perl's internal hash settings and re-starting the interpreter.

      Regards,
      -- Hauke D

[reply]

        Hi,

        Lets say we have this hash:

        $hash{a} = 0;
$hash{b} = 1;
$hash{c} = 0;
$hash{d} = 3;

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        The expected output is:

        a = 0
c = 0
b = 1
d = 3

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        or

        c = 0
a = 0
b = 1
d = 3

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        (note how 'a' & 'c' are switched)

        Both are correct!

        However, for consistency, I rather have always the same output.

        The code that I'm using is:

        foreach my $k ( sort { $hash{$a} <=> $hash{$b}  } keys %hash  ) {
    print "$k = $hash{$k}\n";
}

        [download]

        Thx

        Guy

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