You're sure '$tmp1' is safe? What if it's ' unlink "/etc/passwd"' and you later call the sub? (Ok, so if its Windows, what if its something equally horrible?). What if some evildoer replaces the file you're reading with evil things? Are you sure you want to call eval with quotes instead of block delimiters?

Update: Ok, I missed the qq, that just makes it a little trickier. What if $tmp1 is '@{[unlink "/"]}' ?

I don't see the need to call eval anyway, use a closure:

# I assume this is just an example, as '$c' and '@a' serve
# no real purpose here
my $sub;
{
 my $tmp = $tmp1;
 # You could even skip assigning to '$tmp' if '$tmp1'
 # already 'enclosed' in another limited context
 $sub = sub { my $c = shift; my @a = ($tmp); return @a; };
}
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More update: I see this doesn't account for eval'ing the substitutions you're making, but I would rethink those also, the way you are 'calling' the 'template::gettmplsub' sub it will not get executed anyway. (Hmm, I guess it will later...)