UNIX for Dummies Questions & Answers

awk 'NR==FNR{A[$1]=$0;next}$1 in A{print A[$1]}' file2.txt file1.txt

open (MYFILE, "file1.txt"); 
my @extract;
   while ($record = <MYFILE>) {
      chomp($record);
      open (MYFILE1, "file2.txt");
      
    while ($record1 = <MYFILE1>) {
         chomp($record1);
        @line_array = split ("\t",$record1);
        my $id1 = $line_array[0];
        my $ind = $line_array[1];
        my $sire =$line_array[2];
        my $dam = $line_array[3];
         
    if ($record==$id1){
               push (@extract, "\n$record\t");
            push (@extract, "$ind\t");
            push (@extract, "$sire\t");
        push (@extract, "$dam");
         }
}
      close(MYFILE1);
   }
   close(MYFILE);

my $outfile1 = "ordered_extracted_info.txt";

print "\nwrting results to a file\n";
       open TEST, ">$outfile1" || die "Cannot open $outfile1 $!\n";
       print TEST "sample_id\tindividual_id\tsire\tdam@extract";
       close TEST;