regarding the return code from system, here's a perldoc -f system snippet:

               The return value is the exit status of the program
               as returned by the "wait" call.  To get the actual
               exit value divide by 256. 
    -- snip --
               You can check all the failure possibilities by
               inspecting "$?" like this:

                   $exit_value  = $? >> 8;
                   $signal_num  = $? & 127;
                   $dumped_core = $? & 128;

See also the $? section in perldoc perlvar. In brief, it is The status returned by the last pipe close, backtick ("``") command, successful call to wait() or waitpid(), or from the system() operator.