arr1=("File1","User1");
@arr2=("File2","User2");
open fin,"+<","arr.txt" or die "error";
print fin "@arr1\n";
print fin "@arr2";
print "Enter filename:";
$fname=<>;
close(fin);
open fin,"+<","arr.txt" or die "error";
chomp($fname);
while($line=<fin>)
{
        print "\nReading";
        print "\n$line";
        if($line =~ m/$fname\s/)
        {
                print "\nEntered if";
                chomp($line);
                print "\n$line";
                @read=$line;
                push(@read,"User3");
                $line="@read";
                print "\n$line";
                print fin "@read";
        }
}
close(fin);