[syslog-ng] use loggen to insert content of a file into local log file

[Fabien Wernli]

Hi Victor,

Loggen generates random messages. If you want to provide your own, you can
only do so using loggen's -R and -l switches:

    # loggen -h
    Usage:
		  loggen [OPTION...]  target port
		[...]
		-R, --read-file=<filename>                 Read log messages from
file
		-l, --loop-reading                         Read the file specified
			  in read-file option in loop (it will restart the reading if reached
			  the end of the file)