ct - Dials an attached terminal and issues a login process
ct [-hv] [-sspeed] [-wnumber] [-xnumber] telephone_number
The ct command enables a user on a remote terminal to communicate
with the Tru64 UNIX operating system over a telephone
line attached to a modem at each end of the connection.
Prevents ct from hanging up the current line to answer an
incoming call. Sets the data rate where speed is
expressed in baud. The default is 1200 baud. Allows ct
to send a running narrative to standard error output.
Specifies number as the maximum number of minutes that ct
is to wait for a line. The command then dials the remote
modem at 1-minute intervals until the connection is established
or the specified time has elapsed. Used for debugging.
Produces detailed information about the command's
execution on standard error output on the local system.
The debugging level, number, is a single digit between 0
and 9. The recommended default is 9. Specifies the telephone
number of the modem attached to the remote terminal.
telephone_number can include the digits 0 - 9, - (dashes)
representing delays, = (equal signs) representing secondary
dial tones, * (asterisks), and # (number signs).
The phone number can contain a maximum of 31 characters.
Once ct establishes a connection, a user on the remote
terminal can log in and work on the system.
A user on the local system issues ct with the appropriate
telephone number to call the modem attached to the remote
terminal. When the connection is established, ct issues a
login prompt that is displayed on the remote terminal. A
user on the remote terminal enters a username at the
prompt, and the operating system opens a new shell. The
person using the remote terminal then proceeds to work on
the system like a local user.
However, if there are no free lines, the ct command displays
a message to that effect and asks if the local user
wants to wait for one. If the reply is no, the ct command
hangs up. If the local user wants to wait for a free
line, the ct command prompts for the number of minutes to
wait. The ct command continues to dial the remote system
at 1-minute intervals until the connection is established
or until the specified amount of time has elapsed.
In order to establish a ct connection, the remote user
contacts the local user with a regular telephone call and
asks the local user to issue the ct command. However, if
such connections occur regularly at your site, your system
manager might prefer that a specified local system automatically
issues the ct command to one or more specified
terminals at certain designated times.
The ct command is useful in the following situations: When
a user working offsite needs to communicate with a local
system under strictly supervised conditions. Because the
local system contacts the remote terminal, the remote user
does not need to know the telephone number of the local
system. Additionally, the local user issuing the ct command
can monitor the work of the remote user. When the
cost of the connection should be charged either to the
local site, or to a specific account on the calling system.
If the remote user has the appropriate access permission
and can make outgoing calls on the attached modem,
that user can make the equivalent of a collect call. The
remote user calls the specified local system, logs in, and
issues the phone number of the remote terminal without the
-h option. The local system hangs up the initial link so
that the remote terminal is free for an incoming call, and
then calls back to the modem attached to the remote terminal.
After the user logs out, ct prompts the user on the remote
terminal with a reconnect option; the system can either
display a new login prompt or drop the line.
The ct command is not as flexible as the cu command. For
example, you cannot issue system commands on the local
system while connected to a remote system via ct. However,
the ct command does have two features not available
with cu: You can instruct ct to continue dialing the specified
number until the connection is established or a set
amount of time has elapsed. You can specify more than one
telephone number at a time to instruct ct to continue
dialing each modem until a connection is established over
one of the lines.
If you specify alternate dialing paths by entering more
than one number on the command line, ct tries each line
listed in the /usr/lib/uucp/Devices file until it finds an
available line with appropriate attributes, or runs out of
entries. If there are no free lines, ct asks if it should
wait for one, and if so, for how many minutes. The ct
command continues to try to open the dialers at 1-minute
intervals until the specified time is exceeded. The local
user can override this default by specifying a time with
the -wnumber option when entering the command.
In order to establish a ct connection, the remote user
generally contacts a local user (with a regular phone
call) and asks the local user to issue the command.
Before issuing the ct command, be certain that the remote
terminal is attached to a modem that can answer the telephone.
To connect to a modem with an internal number 4-1589 (the
- is optional), enter: ct 41589
The system responds: Allocated dialer at 1200 baud
Confirm hang_up? (y to hang_up) To dial a modem,
with a local telephone number, attached to a remote
terminal (dialing 9 for an outside line and specifying
a 3-minute wait time), enter: ct -w3
9=5551212 To dial a modem, with a long-distance
number, attached to a remote terminal (specifying
an outside line and a five-minute wait), enter: ct
Information about available devices. Dialing code abbreviations.
Initial handshaking on a link. Access permission
codes. Accessible remote systems.
Commands: cu(1), login(1), tip(1), uucico(8), uucleanup(8), uucp(1), uuencode(1), uulog(1), uuname(1),
uupick(1), uusched(8), uusend(1), uustat(1), uuto(1),
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