How do I use a Perl package known only in runtime?

Question

I have a Perl program, that needs to use packages (that I also write). Some of those packages are only chosen in Runtime (based on some environment variable). I don\'t want

Answer 1

Many years later, eval "use $mod_name"; seems to work just fine (as of at least 5.8.8).

The advantage over eval "require $mod_name"; is that the loaded module's default exports are automatically imported; in other words:

eval "use $mod_name";

is the shorter equivalent of

eval "require $mod_name"; $mod_name->import();

Here's a test command, which passes the name of the module via env. variable mod_name, loads and imports the module, then uses an imported function (assumes a POSIX-like shell):

 $ mod_name='Data::Dumper' perl -e 'eval "use $ENV{mod_name}"; print Dumper("hi!")'
 $VAR1 = 'hi!';

^{I may be missing subtleties; if so, please let me know.}