Editing the Systems File

Each entry in the Systems file represents a remote system with which the local system can communicate. The uucp program cannot establish a communications link between the local computer and a remote computer unless the remote system is configured correctly in this file. Every system that communicates with the local system through uucp must have an entry in the Systems file, regardless of which system initiates the connection.

The entries in the Sys terns file include:

• The name of the remote system

• The times when users can establish a connection between the local and the remote system

• Whether the connection uses a hardwired, telephone, or TCP/IP communications link

• The speed at which the line transmits data

• The phone number used with a modem

• Information required to log in to the remote system The syntax for entries in the Systems file is as follows:

System_name Time Caller Class Phone Login

Note that you must have an entry in every field of the Systems file. Use a dash (-) as a placeholder if no other value is appropriate.

17.3.4.1 The System_name Field

The System name field denotes the name of the remote system. System names should be a maximum of seven characters in length. In order to be compatible with some older systems, such names should include only lowercase characters (or digits).

Manually Setting Up the UNIX-to-UNIX Copy Program 17-11

You can list a specific system in the Sys terns file more than once. Each additional entry for a specific system represents an alternative

communications path that uucp will use in sequential order to try to establish a connection between the local and the remote system.

17.3.4.2 The Time Field

The T irne field uses strings that indicate the days of the week and the times of day during which users on the local system can communicate with the specified remote system. For example, the string MoTuTh0800-1730 indicates that local users can contact the specified remote system on Mondays, Tuesdays, and Thursdays between 8:00 a.m. and 5:30 p.m. As indicated in the previous example, day can be a list represented by Mo, Tu, We, Th, Fr, Sa, or Suo Also, you can enter Wk if users can contact the remote system on any weekday, or Any if they can contact the remote system on any day of the week including Saturday and Sunday.

Enter the time at which users can contact the remote system as a range of times, and using 24-hour clock notation (where 0000 is equivalent to midnight). Time ranges can span 0000. For example, if the time range entered is 1800-0600, it means that calls can be made between 6 p.m. and 6 a.m. Conversely, no calls can be made between the hours of 6 a.m. and 6 p.m. Or, if users can communicate with the specified remote system only during morning hours, enter a range such as 0800 -1200.

If users can contact the remote computer at any time of day or night, leave the Time field blank.

You can include mUltiple Time fields by using a comma (,) as a separator.

For example, Wk1800-0600 ,Sa,Su means that users can contact the remote system on any week day at any time, except between the hours of 6:00 p.m. and 6:00 a.m., and at any time on Saturday and Sunday.

You can enter Never in the Time field, indicating that the remote system can never be called. Use Never when the remote system is to initiate all UUCP transactions.

You can also include an optional subfield that specifies the minimum time in minutes between an unsuccessful attempt to reach the remote system and the retry time when UUCP again attempts to communicate with that system.

This subfield is separated from the rest of the string by a semicolon (;). For example, Wk1800-0600,Sa,Sui2 indicates that if the first attempt to establish communications fails, UUCP should continue to attempt to contact the remote system at 2-minute intervals. If you include this subfield, it overrides the default retry time.

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17.3.4.3 The Caller Field

The keywords for the Caller field are ACU for a telephone connection using a modem, System name for a hardwired connection, and TCP for a connection using

TCP/IP.-If you use TCP, a subfield associated with the caller field specifies a conversation protocol. The default is g. There are three other conversation protocols, t, e, and f, which you can specify by entering with a comma and the appropriate letter. These protocols are faster and more efficient than the g protocol.

Use either the t or e protocol to communicate with a site running any version of UUCP based on the OSFIl version.

Use the e and f protocol for a site running a version of UUCP other than OSFIl. Use the t protocol for sites running the Berkeley version of UUCP.

17.3.4.4 The Class Field

The Class field indicates the speed at which the specified hardwired or telephone line transmits data. The speed can be 300, 1200, 2400, 9600 baud or higher for a hardwired device or telephone connection.

Unless it is necessary to enter a specific transmission rate in this field, use the keyword Any. This keyword instructs UUCP to match any speed that is appropriate for the ACU or system connection that you specified in the Caller field. For a telephone connection, the rate you enter in this field should correspond to the rate you entered in the Class field in the Devices file for this particular ACU. Enter a dash (-) in this field for a TCP/IP connection.

17.3.4.5 The Phone Field

If you are using a hardwired or TCP connection, enter a dash (-) as a placeholder in the Phone field.

If this entry represents a telephone connection using a modem, you can enter the remote modem's phone number in one of the following two ways:

• Enter the complete phone number of the modem. If the system is in your local dialing area, enter the local phone number.

If the system is not in your local dialing area, include any other numbers required to reach the remote modem; for example, numbers for an outside line, long-distance access codes, area codes, or country codes. This type of entry is the most efficient method of including phone numbers if your site uses a small number of telephone connections. However, if your site includes a large number of remote connections established via a phone line and a modem, enter those numbers in the manner described next.

Manually Setting Up the UNIX-to-UNIX Copy Program 17-13

• Enter an optional alphabetic abbreviation that represents the dialing prefix, and any required access and locality codes, and then enter the phone number. If you choose this method, make certain to also include the dialing prefix in the Dialcodes file.

For example, if your site communicates regularly via modems to several systems that are located at the same remote site, it is convenient to replace complete phone numbers of several remote modems with one dial-code abbreviation. Enter the prefix that represents these numbers, together with the unique part of each modem number for each remote system listed in the Systems file.

Then in the Dialcodes file, enter the prefix and the numbers associated with it. Note that you need to enter this prefix in the Dialcodes file only once for all the remote modems listed in the Systems file.

17.3.4.6 The Login Field

The rest of the line after the Phone field is the Login field. The Login field consists of a string of text called the chat script. The chat script defines the conversation that must take place between the local and remote systems before the remote system can establish a connection. The conversation is defined with a series of expect -send characters.

The expect field contains characters that the local system expects to receive from the remote system. Once the local system receives those characters, it sends another string of characters that comprise the send field. For

example, the first expect field generally contains the remote system's login prompt, and the first send field generally contains the login ID to be used on the remote system. The second expect field contains the remote system's password prompt, and the second send field contains the password to be used on the remote system. The expect field can include subfields entered in the following form:

expect [ -send-expect] ...

If the local system does not receive (or cannot read) the first expect string, it sends its own string (the send string within the brackets) to the remote system. The local system then expects to receive another expect string from the remote system. For example, the expect string can contain the following characters:

login:--login:

The local system expects to receive the string login:. If the remote system sends that string and the local system receives it correctly, UUCP goes to the next field in the expect-send sequence. However, if the local system does not receive login:, it sends a null character followed by a new line

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(signified by the absence of a string between the dash (-) string delimiters), and then expects to receive a second login: string from the remote computer.

If the remote system does not send an expect string to the local system, you can enter double quotation marks (" "), representing a null string, in the first expect field. Also, every time the local system sends a field, it automatically transmits a new line following that send field. If you do not want to include this automatic new line, enter \c (backslash c) as the last two characters in the send string.

There are two special strings you can include in the login sequence. The EDT string sends an EDT (end-of-transmission) character, and the BREAK string attempts to send a BREAK character.

You can include the following expect -send strings in login fields in the Systems file:

\N

\b

\c

\d

\p

\E

\e

\K

\n

\r

Expect a null string.

Null character.

Backspace character.

If at the end of a field, suppress the new line that normally follows the characters in a send field. Otherwise, ignore this string.

Delay 2 seconds before sending or reading more characters.

Pause for approximately 1/4 to 1/2 second.

Turn on the echo check (useful in the Dialers file).

Turn off the echo check (useful in the Dialers file).

Send a BREAK character. This is the same as entering BREAK.

New line character.

Carriage return.

Manually Setting Up the UNIX-to-UNIX Copy Program 17-15

\s

\t

\\

EOT

Space character.

Tab character.

Backslash character.

EOT character. When you enter this string, the system sends two EOT

newline characters.

BREAK

BREAK character.

\ddd

Collapse the octal digits (ddd) into a single character and send that character.

The following example is typical of entries in the Systems file:

host1 Any ACU 1200 ch6412 login:--login: uucp word: \ sysuucp

The first field is the name of the remote system (hostl), the second is the time during which users can reach the remote system (Any), the third is the caller (ACU) used for the connection, the fourth is the transmission rate (1200), the fifth is the phone number of the remote modem (ch6412), and the sixth is the login sequence (login: --login: uucp word:

sysuucp).