Re-Tail is a command line program which is intended as an intelligent
incremental logfile reader. It will read a file or group of files
given on the command line, and output any changes since last time it
read the file(s) in question. It will attempt to compensate if the
filesize changes unexpectedly, and will also attempt to compensate if
the file contents changes as well. It is not a very complex program.

WWW: http://xjack.org/retail/