[lug] Bletcherous pipe, FIXME!

[Andrew Gilmore]

Very cool responses.

I agree that the sed needed alteration. Not sure where the extra space went, but indeed it needed to be
sed -e 's/  */ /'
The echo at the end should have been outside the loop. 

hosts.allow needs the dest and the mask, not the gateway, so with this minor change, I like your result:

{
  printf "ALL: localhost"
  route -n | egrep -v '^(0|169|[A-Z])' |    # grab the local
                                            #   hosts/masks
  while read dest gateway genmask etc; do   # turn into
                                            #   comma-separated list
    printf ", $dest/$genmask"
  done
  echo                                      # newline on the end
} >> /etc/hosts.allow                       # tack onto the
                                            #   hosts.allow file