Why I am not getting "success" with this program? - perl

Question

I have written the following program with the hope of getting success. But I could never get it.
my $fileName = 'myfile.txt';
print $fileName,"\n";
if (open MYFILE, "<", $fileName) {
my $Data;
{
local $/ = undef;
$Data = <MYFILE>;
}
my #values = split('\n', $Data);
chomp(#values);
if($values[2] eq '9999999999') {
print "Success"."\n";
}
}
The content of myfile.txt is
160002
something
9999999999
700021

Answer 1

Try splitting by \s*[\r\n]+
my $fileName = 'myfile.txt';
print $fileName,"\n";
if (open MYFILE, "<", $fileName) {
my $Data;
{
local $/ = undef;
$Data = <MYFILE>;
}
my #values = split(/\s*[\r\n]+/, $Data);
if($values[2] eq '9999999999') {
print "Success";
}
}

Answer 2

If myfile.txt contain carriage return (CR, \r), it will not work as expected.
Another possible cause is trailing spaces before linefeed (LF, \n).

Answer 3

You don't need to read an entire file into an array to check one line. Open the file, skip the lines you don't care about, then play with the line you do care about. When you've done what you need to do, stop reading the file. This way, only one line is ever in memory:
my $fileName = 'myfile.txt';
open MYFILE, "<", $fileName or die "$filename: $!";
while( <MYFILE> ) {
next if $. < 3; # $. is the line number
last if $. > 3;
chomp;
print "Success\n" if $_ eq '9999999999';
}
close MYFILE;

Answer 4

my $fileName = 'myfile.txt';
open MYFILE, "<", $fileName || die "$fileName: $!";
while( $rec = <MYFILE> ) {
for ($rec) { chomp; s/\r//; s/^\s+//; s/\s+$//; } #Remove line-feed and space characters
$cnt++;
if ( $rec =~ /^9+$/ ) { print "Success\n"; last; } #if record matches "9"s only
#print "Success" and live the loop
}
close MYFILE;
#Or you can write: if ($cnt==3 and $rec =~ /^9{10}$/) { print "Success\n"; last; }
#If record 3 matches ten "9"s print "Success" and live the loop.