#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11147822
use warnings;

use Path::Tiny;
path("/tmp/11147822.$_.txt")->spew( <<END ) for 1 .. 100; # FIXME for testing only
foo     73
bar     35
word    27
blah    23
END

open my $fh, '-|', 'sort /tmp/11147822.*.txt' or die; # FIXME for your file list
open my $tosort, '|-', 'sort -n -k2' or die;
<$fh> =~ /^(\w+)\s+(\d+)/ or die;
my ($name, $value) = ($1, $2);
while( <$fh> )
  {
  if( /^(\w+)\s+(\d+)/ )
    {
    if( $1 eq $name ) { $value += $2; }
    else
      {
      print $tosort "$name\t$value\n";
      ($name, $value) = ($1, $2);
      }
    }
  }
print $tosort "$name\t$value\n"; # be sure to print last one
close $tosort or die;

##</code><code>##

blah    2300
word    2700
bar     3500
foo     7300