use strict;
use warnings;
use File::Find;

my @files;
my @dirs = qw(/some /list /of /dirs);

sub findstuff {
   my $file = $File::Find::name;
   return unless -f "$file";
   if (grep { /regex/ } "$file") {
      print "Found regex in $file\n";
      push @files, $file;
   }
}

find(\&findstuff, @dirs);
print "Results:\n@files\n";