Re: What is the purpose of local *_ = \my $a in File::Find?

in reply to What is the purpose of local *_ = \my $a in File::Find?

local $_ could be used to localize $_, but that doesn't remove any magic associated with it on some versions of Perl.

$ perl -wE'for ($|) { local $_; $_ = "abc"; say; }'
Argument "abc" isn't numeric in scalar assignment at -e line 1.
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local *_ would do the trick by forcing an entirely new $_ to be created, but that also gets rid of @_, %_, etc.

$ perl -E'$_="x"; @_=(4,5); say $_,@_; local *_; say $_,@_;'
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Assigning to a glob is weird, though. It only assigns to the relevant slot. So that means assigning a reference to a scalar to *_ only replaces $_

$ perl -E'$_="x"; @_=(4,5); say $_,@_; local *_ = \my $a; say $_,@_;'
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Any fresh scalar would have worked.

Note that this aliases $_ to the scalar, but File::Find does not take advantage of that feature.

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Re^2: What is the purpose of local *_ = \my $a in File::Find? by YenForYang (Beadle) on May 16, 2018 at 05:27 UTC
Awesome, thanks for the explanation. What do you mean though by Note that this aliases $_ to the scalar, but File::Find does not take advantage of that feature. Specifically the part about not taking advantage of the feature. What features could be taken advantage of? Thanks EDIT: Oh wait are you saying that `$a` could be used like $_ (they become equivalent?). Or is there something else?	[reply] [d/l]
Re^3: What is the purpose of local *_ = \my $a in File::Find? by ikegami (Patriarch) on May 17, 2018 at 00:54 UTC
`$ perl -E'local *_ = \my $s; $_ = 123; say $s; $s = 456; say $_;' 123 456` [download]	[reply] [d/l]

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