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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
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), uux(1)