If the startup file doesn't include any modules that require the mod_perl runtime environment during their loading, you can validate its syntax with:

panic% perl -cw /home/httpd/perl/lib/startup.pl

The -c switch tells Perl to validate only the file's syntax, and the -w switch enables warnings.

Apache::DBI is an example of a module that cannot be loaded outside of the mod_perl environment. If you try to load it, you will get the following error message:

panic% perl -MApache::DBI -c -e 1
Can't locate object method "module" via package "Apache" 
(perhaps you forgot to load "Apache"?) at 
/usr/lib/perl5/site_perl/5.6.1/Apache/DBI.pm line 202.
Compilation failed in require.
BEGIN failed--compilation aborted.

However, Apache::DBI will work perfectly once loaded from within mod_perl.