The output format consists of the last Message-ID in the history file, followed by a sorted list of host pairs and counts. Here's a sample:
Last-ID: <24524@oliveb.olivetti.com> 42814 epimass!pyramid 22610 pyramid!ames 12824 pyramid!decwrl 7854 ames!mailrus 5426 oliveb!ames 5391 ames!pasteur 5212 decwrl!ucbvax < lots more >
If an input file argument is given, it should be the name of a previous output of newspaths. The file and counts are read in, and the history file is scanned until the Last-ID is found. Normal processing begins with the next article given in the history file. The idea is to be able to continue to accumulate the counts over long periods of time (despite expire runs) and to count each article only once. It is an error if the given Message-ID is not found in the history file.
newspaths old-output > new-output mv new-output old-output
After 1 month of operation at epimass , the resulting output is 135K bytes long.