Code before warnings are enabled at line 14, column 1.  See page 431 of PBP.  (Severity: 4)
Return value of "close" ignored at line 46, column 3.  Check the return value of "close" for success.  (Severity: 2)
Two-argument "open" used at line 51, column 1.  See page 207 of PBP.  (Severity: 5)
"die" used instead of "croak" at line 51, column 44.  See page 283 of PBP.  (Severity: 3)