P:\test>perl -wc junk.pl
Global symbol "$c" requires explicit package name at junk.pl line 8.
Global symbol "$rv" requires explicit package name at junk.pl line 9.
Global symbol "$c" requires explicit package name at junk.pl line 10.
Global symbol "$c" requires explicit package name at junk.pl line 11.
Global symbol "$c" requires explicit package name at junk.pl line 12.
Global symbol "$c" requires explicit package name at junk.pl line 12.
Global symbol "$c" requires explicit package name at junk.pl line 17.
Global symbol "$rv" requires explicit package name at junk.pl line 22.
Global symbol "$c" requires explicit package name at junk.pl line 22.
junk.pl had compilation errors.