You could grep them out of the symbol table:

my @subs = grep { defined &{ $_ } } keys %Your::Package::;
[download]

Update: I probably should have also mentioned that if you're doing this from a different package, you'll need to prepend the package name to make sure you're checking for defined-ness in the right symbol table. E.g.

package Foo; 

sub foo { } 
sub bar { } 
sub baz { }

package Bar; 
my @subs = grep { defined &{ "Foo::$_" } } keys %Foo::; 
print join "\n", @subs;
[download]