pattern matching

[broloc]

Hi all,
i got problem about pattern matching.Could u all please give me some idea how i can do pattern macthing between 2 file.
ok this is the scenario..
i got file A and file B.File A is existing data and File B is a downloadable data.What i'm going to do is i want to update file A using file B.This is my coding.i think there are a lot of mistake.I'm glad if u all could give me an idea or an advice.tq

open (INPUT, "customize_rule.txt&quot || die "can't open file";
#my @Rule = <INPUT>;

$pattern = 'IDS\d{2,3}';

while (<INPUT>)
{

if (/$pattern/)
{
$t = $_;
#print &quot;$t\n&quot;;
#print &quot;$1\n&quot;;
open (OUT, &quot;existcustomize.txt&quot || die &quot;can't open file&quot;;
while (<OUT>)
{
if ($t ne $_)
{
open (CUSTOMIZE, &quot;>>existcustomize.txt&quot || die &quot;can't open file&quot;;
print CUSTOMIZE $t;
print &quot;$t\n&quot;;
last;

}
else
{
print &quot;rule already exist\n&quot;;
last;
}
}

}

}
print &quot;\n\n&quot;;
close(INPUT);
close(OUT);
close(CUSTOMIZE);

 

[icrf]

How do you need to &quot;update&quot; the new file? Need examples of the data to create a pattern to match it. ----------------------------------------------------------------------------------
...but I'm just a C man trying to see the light

 

[broloc]

opss sorry i forgot..ok the data looks like this
alert TCP $external any->$internal any (msg: &quot;ISD282/shellcode....)

i just want to update the data according to the IDS num.if the IDS num for example 'IDS282' not exist in the file A so it will take sentence IDS282 and copy it to file B.

it that clear 4 u...
i really hope that u can help me...