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.
-h Prevents ct from hanging up the current line to answer an incoming
Sets the data rate where speed is expressed in baud. The default is
-v 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 inter-
vals until the connection is established or the specified time has
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 ter-
minal. 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 ter-
minal. 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 termi-
nal 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
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 desig-
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 con-
tacts 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 ct command is not as flexible as the cu command. For example, you can-
not issue system commands on the local system while connected to a remote
system via ct. However, the ct command does have two features not avail-
able 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.
1. In order to establish a ct connection, the remote user generally con-
tacts a local user (with a regular phone call) and asks the local user
to issue the command.
2. Before issuing the ct command, be certain that the remote terminal is
attached to a modem that can answer the telephone.
1. To connect to a modem with an internal number 4-1589 (the - is
The system responds:
Allocated dialer at 1200 baud
Confirm hang_up? (y to hang_up)
2. 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
ct -w3 9=5551212
3. 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 -w5 9=15555551212
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), uuen-
code(1), uulog(1), uuname(1), uupick(1), uusched(8), uusend(1), uustat(1),