use strict; use warnings;

my @eachline = (
  "transaction blah find blah blah think blah save_param",
  "start_sub blah url blah blah submit transaction blah find"
);

my @keywords = qw{transaction find think save_param start_sub url submit};

my %count;

for my $line (@eachline) {
  for my $pattern (@keywords) {
    $count{$pattern} += ($line =~ /$pattern/g);
  }
}

print "No. of matches for $_ is $count{$_}\n" for @keywords;