Thanks for you reply era. THis is the code i am using to fetch the number value in between <cd>????</cd> .. but this is the case when this tag is in the same way in all files .. but when </ab><cd>????</cd> this is the case where this will not be able to handle ..
i am little confused about how to fit in ur code here .. can you help me on this .. i really appreciate it.. Thanks--

foreach my $file (@array_files){
open(fh,">>","tmp.out");
# if (m%<cd>(.*?)</cd>%) { $stuff = $1 }
print fh `tail $file|grep "^<cd>"|grep "</cd>"| cut -d"<" -f 2|cut -c 4-`;
close fh;
}