Grep would probably be a better way to do this.

my $count = grep /match/, <DATA>;
print $count;

__DATA__

match123123
match3123
nomat
not34234
match
4232434
[download]

This outputs 3.
or my golfing solution(a little shorter):

print scalar(grep /match/, <DATA>);
[download]

Update: Fixed my grammar.