Shell Programming and Scripting

Dear experts,

Below i have mentioned two alarms with MAJOR severity, i am intrested only with alarm contains text tre , actually i want to filter out alarm which is highlighted in bold text in some other file for further processing.

I need all above three line of the alarm containing text tre

Please help me with this......

SEV="MAJOR": RX-TX [10] HW-FAILURE [239] DOMAIN="alcomc2_BSS_52
unit-type % bts nbr % 5
SBL-type % ra nbr % 1 subnb % 255

SEV="MAJOR": RX-TX [10] HW-FAILURE [239] DOMAIN="alcomc2_BSS_20
unit-type % bts nbr % 24
SBL-type % tre nbr % 4 subnb % 255


Thanks a lot.
Best Regards.

Code:

open(FH,"<a");
while(<FH>){
	$array[$.%3]=$_;
	if((index $array[0],"tre")!=-1){
		print $array[1];
		print $array[2];
		print $array[0];
	}
}
close(FH);

Dear Cherry,

Thanks a lot for the script,
I am using your script like mentioned below:
This help.txt file contains all the alarms, is it ok because it is not running on my system, dear can you please tell me from this script how can i filter out my desired alarm in other file.

THANKS A LOT.

open(help.txt,"<a");
while(<help.txt>){
$array[$.%3]=$_;
if((index $array[0],"tre")!=-1){
print $array[1];
print $array[2];
print $array[0];
}
}
close(help.txt);

Dears Friends,

Kindly help me with this any idea will be highly appriciated.

Thanks a lot.
Best Regards.