Another alternative would be the little-used trick of assigning to @ARGV. You can then read each line of all of the files in turn using the diamond operator, <>.

@ARGV = qw(testhere.pl closure.pl hello.pl);

my $semi_count;
$semi_count += tr/;// while <>;
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Update: Less patronising, more informative.

--
<http://www.dave.org.uk>

Perl Training in the UK <http://www.iterative-software.com>