Shell Programming and Scripting

IMSHRATE_043008_101016
9820101 A982005000CAVG 030108 000000000000010169000MAR 2008 9820102 MAR 2008 D030108
9820101 A982005000CAVG 030109 000000000000010169000MAR 2008 9820102 MAR 2008 D030108
9820101 A982005000CAVG 043008 000000000000010169000MAR 2008 9820102 MAR 2008 D030108

MSHRATE_043008_101016
9820101 A982005000CAVG 030108 000000000000010169000MAR 2008 9820102 MAR 2008 D030108
Smaller than header
9820101 A982005000CAVG 030109 000000000000010169000MAR 2008 9820102 MAR 2008 D030108
Bigger than header
9820101 A982005000CAVG 043008 000000000000010169000MAR 2008 9820102 MAR 2008 D030108
Equal with header

open FH,"<a.txt" or die "Can not open file\n";
my @arr=<FH>;
close FH;
$arr[0]=~m/(.*)_([0-9][0-9])([0-9][0-9])([0-9][0-9])_(.*)/;
$header=$4.$2.$3;
print $arr[0];
for($i=1;$i<=$#arr;$i++){
	my @temp=split(" ",$arr[$i]);
	$temp[2]=~m/([0-9][0-9])([0-9][0-9])([0-9][0-9])/;
	my $body=$3.$1.$2;
	print $arr[$i],($body>$header)?"Bigger than header\n":($body==$header)?"Equal with header\n":"Smaller than header\n";
}