in reply to can the default file handle be localized?

use Sub::ScopeFinalizer qw( scope_finalizer );

{
   my $old_fh = select($fh);
   my $sentry = scope_finalizer { select($old_fh); };
   ...
}

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Sub::ScopeFinalizer

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Re^2: can the default file handle be localized?
by hbm (Hermit) on Mar 12, 2009 at 21:44 UTC
[reply]

      The OP wants the file handle to be restored automatically on scope exit. The linked node does not provide a means of doing so.

      In fact, Scope::Finalizer could have been used in that post too. 

      use Sub::ScopeFinalizer qw( scope_finalizer );

{
   open(my $old_stdout, '>&', *STDOUT) or die;
   my $sentry = scope_finalizer {
      close(STDOUT);
      open(STDOUT, '>&', $old_stdout) or die;
   };

   close(STDOUT);
   open(STDOUT, '>', $file) or die;

   ...
}

      [download]

      The only reason I didn't is that "..." is a call to system, and that doesn't die or otherwise exit the block.

      Update: I missed it since the point of the linked post was to avoid using local *STDOUT in the circumstances of that thread, but local *STDOUT is a simpler alternative to using select + scope_finalizer: 

      {
    local *STDOUT = $OLDFH;
    ...
}

      [download]
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