My apologies about the previous submit. Hit the create button mistakenly. It is formatted better now.

Thank you Anonymous Monk. The column numbers vary by file. I have below a perl script where I first split the file using awk in bash then try to merge each file to a file with the row names. There is also another file that I used that split the file on tab across each row then place the first element of array in a scalar variable. Then I tried adding the first element and the remaining elements to a hash

The first code

 #!/usr/bin/perl -w
use strict;        
use warnings;
use diagnostics;
use Getopt::Std;

#reading options
our ($opt_i);
getopts('i:');
if (!$opt_i) {
    print STDERR "\nInput file name (-i) required\n\n\n";
}
#open the file or die
open INFILE, "<", $opt_i or die "No such input file $opt_i";

while (<INFILE>) {
chomp;
my @fh = <INFILE>;

my @fh = split ('\t', $_);
#print "@fh";
    my $geno = shift @fh;
    
    
#open directory. the "." represents current directory
opendir(DIR, ".");

#place all files in an array
#@files = readdir(DIR);
    my @files = glob("*.txt");

#close directory
closedir(DIR);
my @merge;

#process each file
    foreach my $file (@files) {
    open FILE, "<", $file;
    
    while(my @line = <FILE>) {
        foreach my $comb (@line) {

        print "$geno\t"."$comb";
    close FILE;
     
    }
        
}
}
}
close INFILE;
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The second code, which is splitting the file

 #!/usr/bin/perl -w

use strict;            
use warnings;
use diagnostics;
use Getopt::Std;

#reading options
our ($opt_i);
getopts('i:');
if (!$opt_i) {
    print STDERR "\nInput file name (-i) required\n\n\n";
}
#open the file or die
open INFILE, "<", $opt_i or die "No such input file $opt_i";

my %file;
while (<INFILE>) {
#remove the newline character
chomp;

#create an array
my @fh = <INFILE>;

#split the file by tabs in each row
@fh = split ('\t', $_);
#place the first column (row names) in $geno
    my $geno = shift @fh;

  my $remain = join "_", @fh[1-];
    push @{$geno{$remain}}, $_;
}
# print the first field (the username)
 print "%file\n";
}
close INFILE;
[download]