Shell Programming and Scripting

my $logFile = $ARGV[0]; 
die "usage: $0 <logFile>" unless $logFile; 
die "Logfile $logFile doesn't exist" unless -f "$logFile"; 
open(my $log, "<", $logFile) or die "Can't open $logFile for reading."; 
print "Processing file $logFile...\n"; 
#my $authenticates = {}; 
my $n = 0;
my $ArcotIDError_Count = 0;
my $QnAError_Count = 0;
my $UPError_Count = 0;
my $OTPError_Count = 0;
my $errorCode;
while(my $line = <$log>) { 
   	$n++; 
    $line =~ tr/\r\n//d; 
	if($line =~ /Handling NSPAdvice for mechanism \[4\]/) {
		while ( $line = <$log> ) {
			if ($line =~ /Authentication mechanism returned \[(\d+)\]/) {
				my $errorCode = $1;
				print "$errorCode\n";
				if ($errorCode != 0 && $errorCode != 1) {
                  $ArcotIDError_Count++;
				}
			}
			next;
		}
	}	
	}
	print "Total Number Of ArcotID Authentication ErrorCode returned is $ArcotIDError_Count\n";

if($line =~ /Handling NSPAdvice for mechanism \[4\]/)
as
if($line =~ /Handling NSPAdvice for mechanism \[4\]/ || /Handling NSPAdvice for mechanism \[3\]/)