There is no PERL. The name of the language is Perl, the name of the interpreter is perl. And perl is typically NOT a shell.

In Perl, you don't want to mess with sqlplus. You use DBI and DBD::Oracle. Errors can be handled "as usual" (i.e. eval {} and $@) if you use set the RaiseError attribute of the database handle, typically by including it in the attr hash of the DBI connect method.

Alexander