AT&T UNIX™PC Unix System V Users Manual - tenox

CU ( lC ) CU ( lC )
NAME cu - call another UNIX system
SYNOPSIS
cu [ -sspeed ] [ -lline ] [ -h ] [ -t ] [ -d ] [ -m] [-ol -e ]
telno I dir
DESCRIPTION
Cu calls up another UNIX system, a terminal, or possibly a non­
UNIX system. It manages an interactive conversation with possible
transfers of ASCII files. Speed gives the transmission speed
( llO, 150, 300, 600, 1200, 4800, 9600); 300 is the default value.
Most of our modems are either 300 or 1200 baud. For dial out
lines, cu will choose a modem speed (300 or 1200) as the slowest
available which will handle the specified transmission speed.
Directly connected lines may be set to speeds higher than 1200
baud.
The -1 value may be used to specify a device name for the communications
line device to be used. This can be used to override
searching for the first available line having the right speed. The -s
option allows the user to override the line speed specified in the
file fusr/lib/uucpfL-devices. However, if the -s option is not used,
the line speed will be taken from the L-devices file. The -h
option emulates local echo, supporting calls to other computer systems
which expect terminals to be in half-duplex mode. The -t
option is used when dialing an ASCII terminal which has been set
to auto-answer. Appropriate mapping of carriage-returns to
carriage-return-line-feed pairs is set. The -d option cause diagnostic
traces to be printed. The -m option specifies a direct line
which has modem control. The -e ( -o) option designates that
even (odd) parity is to be generated for data sent to the remote.
The -d option causes diagnostic traces to be printed. Telno is
the telephone number, with '=' (equal signs) for secondary dial
tone. ':' (colons) for pausing 10 seconds, and for pausing 2 seconds
at appropriate places. The string dir for telno may be used for
directly connected lines, and implies a null ACU. Using dir
insures that a line has been specified by the -1 option. When
using the internal modem line, phO and ph1 make sure the phone
status of the line to be used shows DATA, otherwise the call will
fail. The phone line supports 300 and 1200 for the -s option.
Cu will try each line listed in the file fusrflibfuucpfL-devices
until it finds an available line with appropriate attributes or runs
out of entries. After making the connection, cu runs as two
processes: the transmit process reads data from the standard input
and, except for lines beginning with -, passes it to the remote system;
the receive process accepts data from the remote system
and, except for lines beginning with -, passes it to the standard
output. Normally, an automatic DC3/DC1 protocol is used to control
input from the remote so the buffer is not overrun. Lines
beginning with - have special meanings.
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