Created attachment 291 [details]
Specifying a non-existent PCI network interface results in packet capture on
all valid network interfaces on the host.

When specifying a non-existent network interface or any PCI network interface,
all valid PCI network interfaces are captured. The reason is in the static void
select_interface(const char arg) function, which was intended to match all
network interfaces when specified with the '' character. However, the if
(strcmp(arg, "")) selects all interfaces. After modification to if (strcmp(arg,
"")==0), it works correctly to specify a single network interface.