% perl sample6.pl
[WARN ] main warn message
[ERROR] main error message
[FATAL] main fatal message
% perl sample6.pl -v
[INFO ] main info message
[WARN ] main warn message
[ERROR] main error message
[FATAL] main fatal message
% perl sample6.pl
[WARN ] main warn message
[ERROR] main error message
[FATAL] main fatal message
% perl sample6.pl -v
[INFO ] main info message
[WARN ] main warn message
[ERROR] main error message
[FATAL] main fatal message