That surprises me, and I wonder why .*? is somewhat faster than a more explicite pattern.

However, I'd still shy away from using .*?. Consider the effect of a slight change of the string we are matching against (basically, replacing the \cB with \cA): 

 
use Benchmark qw( cmpthese );
   
my $ad = <<'__EOI__';
------ Yahoo
meow meow meow meow meow meow meow meow
woof woof woof woof
jabberwocky
foo bar! foo!!
__EOI__
 
my $email = join '',
            map chr(rand(26)+ord('a')),
            1..2000;
 
 
our $file = "$email\n$ad\cA" x 1000;
cmpthese(-3, {
   ikegami        => 'use strict; use warnings; my $x = our $file; $x 
+=~ s/-----
- Yahoo.*?(?=\cB)//sg;',
   JavaFan        => 'use strict; use warnings; my $x = our $file; $x 
+=~ s/-----
- Yahoo[^\cB]*+//g;',
   JavaFan_noplus => 'use strict; use warnings; my $x = our $file; $x 
+=~ s/-----
- Yahoo[^\cB]*//g;',
});
__END__
            (warning: too few iterations for a reliable count)
                  Rate        ikegami        JavaFan JavaFan_noplus
ikegami        0.264/s             --           -98%           -98%
JavaFan         16.2/s          6053%             --            -1%
JavaFan_noplus  16.5/s          6135%             1%             --

[download]

In reply to Re^4: How do I delete from a delimiter to the end of a file? by JavaFan
in thread How do I delete from a delimiter to the end of a file? by wcw

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