filehandle => sub {
        my @lines;
        open my $str_fh, "<", \$str or die "cannot open fh $!";
        while (<$str_fh>) {
            chomp;
            s/o/i/g;
            push @lines, $_;            
        }
    },

##</code><code>##

perlbrew exec bench_script.pl

# Other versions of Perl, omitted for brevity - see original link
#   for the "gories..."
...

perl-5.26.0
==========
             Rate      index      regex      split filehandle
index      3.00/s         --       -25%       -49%       -53%
regex      3.98/s        33%         --       -33%       -37%
split      5.91/s        97%        49%         --        -6%
filehandle 6.31/s       111%        59%         7%         --

##</code><code>##

perl-5.30.0
===========
             Rate      regex      index      split filehandle
regex      9.98/s         --       -11%       -32%       -33%
index      11.2/s        12%         --       -23%       -25%
split      14.6/s        46%        30%         --        -2%
filehandle 14.9/s        49%        33%         2%         --

##</code><code>##

perl-5.28.1 (Windows 10 Pro)
============================
             Rate      regex      index filehandle      split
regex      8.09/s         --       -14%       -17%       -33%
index      9.46/s        17%         --        -3%       -22%
filehandle 9.73/s        20%         3%         --       -20%
split      12.2/s        50%        29%        25%         --

##</code><code>##

perl -V
=======

==> cc='gcc'
    ccflags =' -s -O2 -DWIN32 -DWIN64 -DCONSERVATIVE -D__USE_MINGW_ANSI_STDIO -DPERL_TEXTMODE_SCRIPTS -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -fwrapv -fno-strict-aliasing -mms-bitfields'                                                                    
    optimize='-s -O2'
    cppflags='-DWIN32'
    ccversion=''
    gccversion='7.1.0'
...
  Built under MSWin32
  Compiled at Dec  2 2018 14:30:03
  @INC:
    C:/Strawberry/perl/site/lib
    C:/Strawberry/perl/vendor/lib
    C:/Strawberry/perl/lib