my $var="zzz\n" unless defined($var)

This is the problem; the behavior of a my declaration in a statement with a conditional modifier is undefined. This is documented in perldoc perlsyn. Convert that to an unless statement: 

unless ( defined $var) { my $var = "zzz\n" }

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and you will get predictable behavior, but, probably, not what you want.

I don't know what you are trying to do, but you might consider using a hash to hold the set of variables that may or may not exist.

Be well,
rir

In reply to Re: conditional definition of variables by rir
in thread conditional definition of variables by stephanm

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