This is a link to the download page for the program tail. Tail was designed and is primarily used on linux systems to monitor the updates to a text file. Basically it continually reads the contents of the file, unlike most programs that make a local copy of a file in memory and then don't read or write to disk until commanded to do so.
This works great for RENDER LOG files!!! Most productions houses have a version or conglomeration of tail programs (combined with grep and sed) that will search for certain text strings like "ERROR" or "Warning" and then highlight them and send an email or beep or notify a database of some sort. These programs combined with scripting languages are the beginings of a render support department that monitors renders every night.
Use this program to in conjunction with the render command to generate a log file of your own like so:
render -r sw -s 389 -log logs/389_CloseUp_6_14.txt scenes/FountainRender.20.mb
Notice the "-log" flag and the specification of a log file that is in your "logs" directory.