From the NannyMUD documentation

LAST CHANGE

2000-12-09

FUNCTION

NAME
        log_file - Log a debug message in a file.


SYNTAX
        void log_file(string file, string message)

DESCRIPTION
        Append a message to a log file. All log files are in the directory
        mudlib/log.


NOTE
        '/log/' is automatically prepended to the file name.


NOTE
        The files are moved to 'file'.old when they are larger than 50 Kb.


SEE ALSO
        write_file in efun/disc_related/write_file