@ARGV = glob 'datafile*';

open my $OUTPUT, '>', 'output_file' or die "Cannot open 'output_file' 
+because: $!";

my %data;
while ( <> ) {
    next unless /^(.+) (\S+)$/;
    push @{ $data{ $1 } }, $2;
    }

for my $key ( sort keys %data ) {
    print join ' ', $key, @{ $data{ $key } }, scalar @{ $data{ $key } 
+}, "columns\n";
    }
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======================== I have files by name datafile1,datafile2,datafile3,datafile4.........datafile200 in a directory. But these files are stored in a a different pattern ...datafile1,datafile10,datafile11,datafile12 and so on. The above program is reading and writing in the same order. I would like to pick data from in the an order from datafile1, 2, 3 to data200. Any suggestions and additions are appreciated. Thank you.