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Systems(4)							   Systems(4)



NAME
  Systems - Contains information about remote systems that can be contacted
  using	the uucp program.

SYNOPSIS

  /usr/lib/uucp/Systems

DESCRIPTION

  The /usr/lib/uucp/Systems file contains an entry for each remote system
  that the local system	can communicate	with using uucp.  The uucp program
  cannot establish a connection	with a remote system unless it has an entry
  in the Systems file.	The Systems files must be configured on	each system
  running the uucp program.

  Note that only someone with root user	authority can edit the Systems file,
  which	is owned by the	uucp login ID.

  Fields in the	Systems	File

  The Systems file should contain a description	of each	system that the	local
  system can establish a remote	connection with.  Each line in the Systems
  file includes	the following fields:

       sys_name	Time Caller Class Phone	Login

  sys_name  The	name of	the remote system.  In general,	names should be	a
	    maximum of seven characters	in length and must be unique.  To
	    insure compatibility with some older systems, names	should only
	    include lowercase characters and digits.

	    There can be more than one entry for each sys_name.	 Each addi-
	    tional entry for a specific	system represents an additional	com-
	    munications	path that uucp will sequentially try if	communication
	    cannot be established using	an earlier entry.

  Time	    Specifies the times	when the local system can call the remote
	    system.  This field	consists of three subfields:  day, for the
	    day	of the week (required),	time, for the time of the day when
	    the	system can call	(optional), and	retry, for the minimum retry
	    period in minutes (optional).  The day and time subfields are not
	    separated with spaces.  The	retry field is separated by a semi-
	    colon.

	    The	day subfield is	specified using	the following keywords:

	    Any	      system can call on any day

	    Never     system can never call the	remote system.	The remote
		      system will have to call the local system.

	    WK	      any weekday.  You	can also use Mo, Tu, We, Th, Fr, and
		      Sa, for example MoWeFr, for Monday, Wednesday, and Fri-
		      day.

	    The	day subfield is	required, unlike the time and retry fields.

	    The	time subfield is specified contains two	times, in 24-hour
	    clock notation, which specify a range of times.  Leave this	sub-
	    field blank	if the remote system can be called at any time during
	    the	day.  For example, if a	remote system can only be called dur-
	    ing	the morning, enter 0800-1200 in	the subfield.

	    The	time subfield can also specify when the	remote system cannot
	    be reached if the time range entered spans 0000.  For example,
	    0800-0600 means the	remote system can be contacted at any time,
	    except between 6:00	am and 8:00 am.

	    Multiple time fields can be	included by using a comma as a
	    separator.	For example, WK1800-0600,Sa,Su means the remote	sys-
	    tem	can be contacted at any	time on	a week day except between
	    6:00 pm. and 6:00 am, and at any time on Saturday and Sunday.

	    The	optional retry subfield, specifies the minimum time, in
	    minutes, before uucp can try again to contact a remote system
	    after an unsuccessful attempt.  This subfield is separated from
	    the	rest of	the string by a	semicolon.  For	example, Any0800-
	    1200;3 specifies that 3 minutes is the minimum period after	which
	    uucico can try this	system again once it has been invoked expli-
	    citly or by	the cron daemon. Usually, uucp will attempt to con-
	    tact the remote system twice and if	uucp fails, it will exit.
	    The	uucp command can be invoked again after	the 3 minute period.

  Caller    Specifies the type of connection to	be used	to communicate with
	    the	remote system.	Use the	ACU keyword for	a telephone connec-
	    tion using a modem or TCP (for a connection	using TCP/IP).
	    Alternatively, sys_name can	be used	for a hardwired	connection.

	    If TCP is used, there is a subfield	which specifies	a conversion
	    protocol.  The default is the g protocol.  Other protocols are e,
	    f, and t which are faster and more efficient than the g protocol.
	    To specify a particular protocol, place a comma and	the protocol
	    letter after TCP, for example TCP,f.

	    The	entry specified	in this	field must have	a corresponding	entry
	    in the /usr/lib/uucp/Devices file.

  Class	    The	speed in bits per second for the device.  Unless it is neces-
	    sary to use	a specific baud	rate, use the keyword Any.  This
	    instructs uucp to match a speed that is appropriate	for the	ACU
	    of system connection specified in the Caller field.

	    For	a telephone connection,	the rate you enter in this field
	    should correspond to a rate	specified in the Class field of	an
	    entry in the /usr/lib/uucp/Devices file.

	    For	a TCP connection, do not specify a baud	rate.  Instead,	use a
	    hyphen, -, as a placeholder.

  Phone	    The	phone number used to reach the remote system.  For a
	    hardwired or TCP connection, use a hyphen, -, as a placeholder.

	    The	phone number can be the	complete phone number of the remote
	    system or a	combination of an alphabetic abbreviation that
	    represents the dialing prefix and the remainder of the number;
	    see	Dialcodes(4).

	    An equal sign, =, in the phone number indicates a wait for a
	    secondary dial tone.  This may be required when a special number
	    sequence must be used to access an outside line, for example.
	    For	modems that do not have	the ability to detect a	secondary
	    dial tone, the = sign generates a pause instead.  A	hyphen,	-, in
	    the	phone number generates a 1-second pause.

  Login	    The	"chat string" which describes the initial conversation
	    between systems to complete	the login procedure.  The string con-
	    sists of "expect-send" pairs (separated by spaces) and optional
	    "subexpect-subsend"	pairs (separated by hyphens).

	    The	"expect" portion contains characters that the local system
	    expects to receive from the	remote system.	The "send" portion
	    contains a string of characters that are sent to the remote	sys-
	    tem	upon receipt of	the "expect" string.  For example, the first
	    expect string generally contains the remote	system's login
	    prompt, and	the first send string generally	contains the login ID
	    to be used on the remote system.  The second expect	string con-
	    tains the remote password prompt and the second send string	con-
	    tains the remote system's password.	 For example,


		 in: uucp word:	sysuucp

	    Note that the expect portion in the	example	contained only the
	    trailing part of the full strings expected,	login: and password:,
	    respectively.  The expect string only needs	to contain part	of
	    what is expected.  This helps to avoid problems with remote	sys-
	    tems that may use Login: or	Password: instead of login: and	pass-
	    word:.

	    The	use of "subexpect-subsend" strings is shown below:


		 in:--in: uucp word: sysuucp

	    In the example, the	local system expects to	receive	the string
	    in:.  If the local system gets that	string,	uucp goes on to	the
	    next field in the "expect-send" sequence, which is uucp.  How-
	    ever, if the local system does not get that	string,	it sends its
	    own	string,	which is enclosed by hyphens after the expect string.
	    In the above example, a null character followed by a newline is
	    sent.  The local system then expects the in: (the second instance
	    of it in the example).  The	newline	sent to	the remote generally
	    causes it to respond with its login	prompt,	and the	login ID can
	    be sent followed by	password processing.

	    The	following strings can be included in the Login field:

	    \N	Null character

	    \b	Backspace

	    \c	Suppress the newline at	the end	of the send string

	    \d	Delay two seconds before sending or reading more characters

	    \p	Pause for approximately	.25 to .50 seconds

	    \E	Turn on	the echo check (useful in Dialers file)

	    \e	Turn off the echo check	(useful	in Dialers file)

	    \K	Send a BREAK character

	    \n	Newline

	    \r	Carriage return

	    \s	Space character

	    \t	Tab

	    \\	backslash character

	    EOT	EOT character.	Two EOT	newline	characters are sent

	    BREAK
		BREAK character	(same as \K)

	    \ddd
		Collapse the octal digits (ddd)	into a single character
		before sending.

	    The	following example is shown below as two	lines due to screen-
	    width limitations.	As a typical example entry in Systems, it
	    would actually be one line:


		 host1 Any ACU 1200 ch6412 ""


		 login:--login:	uucp word: sysuucp

	    In this example, host1 can be called at any	time (Any) using a
	    phone connection (ACU) at 1200 baud.  The phone number is ch
	    (which is defined in the Dialcodes file) followed by 6412.	Ini-
	    tially, the	local system expects nothing (indicated	by "") and
	    sends a sequence of	four carriage returns with two-second delays
	    separating them (\r\d\r\d\r\d\r).  This is typical for a remote
	    system that	must read characters before presenting a login
	    prompt.  Finally, the login	is executed, using login ID uucp and
	    password sysuucp.

FILES

  /usr/lib/uucp/Devices
	    Contains information about available devices

  /usr/lib/uucp/Dialcodes
	    Contains dial-code abbreviations

  /usr/lib/uucp/Dialers
	    Contains information about modems used for uucp communications
	    links

RELATED	INFORMATION

  Daemons: uucico(8)
  Commands: ct(1), cu(1), uutry(1), uucp(1), uucpsetup(8)