error checks in perl scripts

[dmorton]

While helping someone in irc, it was discovered that a typo in a config was causing a file not found error, resulting in a infinite loop in process-quarantine. We need to check for such errors and quit appropriately.

[dmorton]

namely $script_dir and $template_dir

[dmorton]

I can check for these, but there are still problems when the subroutine script cannot run, such as missing libraries - the program gets stuck in an infinite loop.

[dmorton]

I'd like to look into changing this from a system() call to a fork based program, like http://perldoc.perl.org/perlipc.html#Safe-Pipe-Opens

We could preload all the spamassassin objects which would catch a lot of potential errors before getting into a loop... and the forking would still clean up memory from the scanning process. Preloading the spamassassin objects would also serve to speed up the process a little.

[dmorton]

see [1262]