i would call this a bug in the program.  for a start, you're not
using sig{set,long}jmp(3).  additionally interrupting library
routines that may have to open fd's to do their work is a sure
way to lose descriptors.. (this isn't just limited to
gethostbyaddr() doing DNS lookups, but also if it was reading
/etc/hosts, or any other library function.)


.mrg.