Time Field in /etc/uucp/Systems File

This field specifies the day of week and time of day when the remote computer can be called. The format of the Time field follows:

daytime[;retry]

day Portion of Time Field

The day portion can be a list that contains some of the following entries.

Su Mo Tu We Th Fr Sa

For individual days.

Wk

For any weekday.

Any

For any day.

Never

Your host never initiates a call to the remote computer. The call must be initiated by the remote computer. Your host is then operating in passive mode.

time Portion of Time Field

Example 26–1 shows Any in the Time field, which indicates that host Arabian can be called at any time.

The time portion should be a range of times that are specified in 24-hour notation, for example, 0800-1230 for 8:30 a.m. to 12:30 p.m. If no time portion is specified, any time of day is assumed to be allowed for the call.

A time range that spans 0000 is permitted. For example, 0800-0600 means all times are allowed other than times between 6 a.m. and 8 a.m.

retry Portion of Time Field

The retry subfield enables you to specify the minimum time (in minutes) before a retry, following a failed attempt. The default wait is 60 minutes. The subfield separator is a semicolon (;). For example, Any;9 is interpreted as call any time, but wait at least 9 minutes before retrying after a failure occurs.

If you do not specify a retry entry, an exponential back-off algorithm is used. This means that UUCP starts with a default wait time that grows larger as the number of failed attempts increases. For example, suppose the initial retry time is 5 minutes. If no response occurs, the next retry is 10 minutes later. The next retry is 20 minutes later, and so on until the maximum retry time of 23 hours is reached. If retry is specified, the value specified is always the retry time. Otherwise, the back-off algorithm is used.