Don't assign to a global variable without localising it. You just clobbered your parent's data.
Of course, the parent could protect its $_ my using a lexical variable. And so can do_stuff1. local $_ is in idiom I've had no need for the past 2 years. 
sub do_stuff1 {
    my $_ = shift;
    chomp;
    say;
}

[download]
You also wrote:
or even safer: 
sub do_stuff1 {
    local *_;
    $_ = shift;
    ...
}

[download]
Safer? You should test your code if you label it 'safe', or 'safer'. I guess you didn't realize that local *_; also gives you a new value for @_, so you no longer have access to the subs parameters?

In reply to Re^2: style guidance by JavaFan
in thread style guidance by 7stud

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