I could think of this very simple code, it gives you an idea about creating a list, that list is saved in @array and then for each element in the array there happens a match check that increments the count when true, you have each element checked and the checking goes on till all the array elements have been checked for the pattern /\bsaravanan\b/ ...

!/usr/local/bin/perl
$string="a student name is sa\nravanan. saravanan is studying 3rd stan
+dard.i am go with sara\nvanan";
$count = 0;
$string =~s/\n//g;     #removing \n
print "$string\n";


@array = split(" ", $string);      #making the string into individual 
+list elements
foreach $element(@array){
        if($element=~/\bsaravanan\b/){
                $count++;
                }
        }
print "found: $count matches.\n";
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