logtail reads a specified file (usually a log file) and writes
to the standard output that part of it
which has not been read by previous runs of
logtail. It prints the appropriate number of bytes from the end of
logfile, assuming that all changes that are made to it are to add new
characters to it.
logfile must be a plain file. A symlink is not allowed.
logtail stores the information about how much of it has already been read
in a separate file called
offsetfile can be omitted. If omitted, the file named
logfile.offset in the same directory which contains
logfile is used by default.
offsetfile is not empty, the inode of
logfile is checked. If the inode is changed,
logtail simply prints the entire file.
If the inode is not changed but
logfile is shorter than it was at the last run of
logtail, it writes a warning message to the standard output.