use strict;
use warnings;
##</code><code>##

C:\>more client_reg.pl
sub hi{print q,hi,}

C:\>perl -e" do (client_reg.pl);hi()"
Undefined subroutine &main::hi called at -e line 1.

C:\>perl -we" do (client_reg.pl);hi()"
Unquoted string "pl" may clash with future reserved word at -e line 1.
Undefined subroutine &main::hi called at -e line 1.

C:\>perl -Mstrict -we" do (client_reg.pl);hi()"
Bareword "client_reg" not allowed while "strict subs" in use at -e line 1.
Bareword "pl" not allowed while "strict subs" in use at -e line 1.
Execution of -e aborted due to compilation errors.

C:\>perl -Mstrict -we" do q(client_reg.pl);hi()"
hi
C:\>