First steps 

• Some simple commands:

DB<1> R
Warning: some settings and command-line options may be lost!

Loading DB routines from perl5db.pl version 1.28
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

main::(-e:1):   0
DB<1> l
1==>    0
DB<1> h
List/search source lines:               Control script execution:
  l [ln|sub]  List source code            T           Stack trace
  l
[..]