I think I like the basic approach of hdb here (elaborated by vsespb here) best, but if it's absolutely necessary to use  $_ come Hell or high water, maybe something like: 

>perl -wMstrict -le
"for (qw(zik zok)) {
   print qq{for before: '$_'};
   foo('wilma');
   print qq{for after: '$_' \n};
   }
 ;;
 sub foo {
   local $_ = 'fred';
   sub { local $_ = 'XXX';  goto &bar; }->(@_);
   }
 ;;
 sub bar {
   my ($passed) = @_;
   print  qq{gone from foo,  passed = '$passed',  \$_ = '$_'};
   }
"
for before: 'zik'
gone from foo,  passed = 'wilma',  $_ = 'fred'
for after: 'zik'

for before: 'zok'
gone from foo,  passed = 'wilma',  $_ = 'fred'
for after: 'zok'

[download]

Note that local-ization within the calling context of goto (i.e., within the  sub { ... }) is still wiped out.

Note also: Try: 

sub foo {
  for (qw(fred pebbles)) {
    sub { for (qw(hoo ha)) { goto &bar; } }->(@_);
    }
  }

[download]

In reply to Re: How to safely use $_ in a library function? by AnomalousMonk
in thread How to safely use $_ in a library function? by perl-diddler

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.