Entries in the file are variable length. Each log entry has a fixed length header of the form:
struct sockstamp {
short sin_family;
u_short sin_port;
struct in_addr sin_addr;
time_t sin_time;
int sin_len;
};
followed, possibly, by the message received from the IMP Each time the logging process is started up it places a time stamp entry in the file (a header with sin_len field set to 0).
The logging process will catch only those messages from the IMP which are not processed by a protocol module, e.g. IP. This implies the log should contain only status information such as ``IMP going down '' messages, ``host down'' and other error messages, and, perhaps, stray NCP messages.