Code before warnings are enabled at line 19, column 1.  See page 431 of PBP.  (Severity: 4)
Return value of "open" ignored at line 47, column 5.  Check the return value of "open" for success.  (Severity: 3)
Return value of "close" ignored at line 53, column 5.  Check the return value of "close" for success.  (Severity: 2)
Return value of "open" ignored at line 62, column 5.  Check the return value of "open" for success.  (Severity: 3)
Return value of "close" ignored at line 70, column 5.  Check the return value of "close" for success.  (Severity: 2)
Expression form of "eval" at line 112, column 9.  See page 161 of PBP.  (Severity: 5)
String delimiter used with "split" at line 151, column 19.  Express it as a regex instead.  (Severity: 2)
String delimiter used with "split" at line 152, column 19.  Express it as a regex instead.  (Severity: 2)
Return value of "open" ignored at line 304, column 5.  Check the return value of "open" for success.  (Severity: 3)
String delimiter used with "split" at line 308, column 25.  Express it as a regex instead.  (Severity: 2)
Return value of "close" ignored at line 313, column 5.  Check the return value of "close" for success.  (Severity: 2)
Return value of "open" ignored at line 319, column 5.  Check the return value of "open" for success.  (Severity: 3)
Return value of "close" ignored at line 325, column 5.  Check the return value of "close" for success.  (Severity: 2)