When invoked, the daemon creates multiple copies of itself, one copy for each serial line used in the network. Each copy opens the serial line, creates a startup message for the LOG file, and waits for a response from the daemon at the other end. The startup message lists the names of the machines to be connected, the serial line to be used, and the current date and time. If the daemon receives a correct response, it establishes the serial link and adds the message ``first handshake complete'' to the LOG file. If there is no response, the daemon waits indefinitely.
If invoked with the -x switch, the daemon records each transmission in the LOG file. A transmission entry shows the direction of the transmission (tx for transmit, rx for receive), the number of bytes transmitted, the elapsed time for the transmission (in minutes and seconds), and the time of day of the transmission (in hours, minutes, and seconds). Each entry has the form:
direction byte_count elapsed_time time_of_dayThe daemon also records the date and time every hour. The date and time have the same format as described for the date command.
If invoked with the -e switch, the daemon records all transmission errors in the LOG file. An error entry shows the cause of the error preceded by the name of the daemon subroutine which detected the error.
The mailer daemon is normally invoked by the start option of the netutil command and is stopped by the stop option.
During the normal course of execution, the mailer daemon uses several files in the /usr/spool/micnet/remote directory. These files provide storage for LOG entries, commands issued by the remote(C) command, and a list of processes under daemon control.