$ perl -MO=Deparse -wce 'sprintf "%x%x%x", ord ("a"), ord ("b"), ord ("c")'
    Useless use of a constant in void context at -e line 1.
    BEGIN { $^W = 1; }
    '???';
    -e syntax OK  
    $

##</code><code>##

#!/usr/bin/perl
    
use strict;
use warnings 'all';   
    
use Benchmark;
    
timethese -10 => {
    unpack     =>  '$_ = unpack "H*" => "abc"',
    sprintf    =>  '$_ = sprintf "%x%x%x", ord ("a"), ord ("b"), ord ("c")',
}

 
__END__
Benchmark: running sprintf, unpack for at least 10 CPU seconds...
   sprintf: 11 wallclock secs (10.25 usr +  0.00 sys = 10.25 CPU) @ 775053.56/s (n=7944299)
    unpack: 11 wallclock secs (10.48 usr +  0.01 sys = 10.49 CPU) @ 331145.09/s (n=3473712)

##</code><code>##

    $ perl -MO=Deparse -wce '$_ = sprintf "%x%x%x", ord "a", ord "b", ord "c"'
    BEGIN { $^W = 1; }
    $_ = '616263';
    -e syntax OK
    $  

##</code><code>##

    $ perl -MO=Deparse -wce '($a, $b, $c) = split // => "abc";
               $_ = sprintf "%x%x%x", ord $a, ord $b, ord $c'
    BEGIN { $^W = 1; }
    ($a, $b, $c) = split(//, 'abc', 4);
    $_ = sprintf('%x%x%x', ord $a, ord $b, ord $c);
    -e syntax OK
    $

##</code><code>##

#!/usr/bin/perl
 
use strict;
use warnings 'all';
   
use Benchmark;
    
use vars qw /$a $b $c $abc/;

$abc = "abc";
($a, $b, $c) = split // => $abc;

timethese -10 => {
    unpack     =>  '$_ = unpack "H*" => $::abc',
    sprintf    =>  '$_ = sprintf "%x%x%x", ord $::a, ord $::b, ord $::c',
}
       

__END__
Benchmark: running sprintf, unpack for at least 10 CPU seconds...
   sprintf: 11 wallclock secs (10.51 usr +  0.01 sys = 10.52 CPU) @ 208379.75/s (n=2192155)
    unpack: 10 wallclock secs (10.10 usr +  0.00 sys = 10.10 CPU) @ 323836.04/s (n=3270744)