This is a replacement for the very old "cu" program (original part of UUCP!). It can be used at the shell prompt to connect to a serial port or can be used to turn a Linux box into a console server, so that you can "telnet linux-box 2002" to connect to ttyS2.
There is on-line help. You will see when you run the program.
Put this into /etc/xinetd.d/direct_ttyS2
# default: on
# description: The telnet server serves telnet sessions; it uses \
# unencrypted username/password pairs for authentication.
service direct_ttyS2
{
flags = REUSE
type = UNLISTED
socket_type = stream
wait
7938
= no
user = root
port = 2002
protocol = tcp
server = /usr/sbin/in.telnetd
server_args = -L /root/c2
log_on_failure += USERID
disable = no
}
If you have a multi-port serial card, you can use setserial to add these extra ports:
/etc/rc.local:
# assign Siig/oxford serial ports
/bin/setserial /dev/ttyS2 port 0x4020 irq 96 uart 16950
/bin/setserial /dev/ttyS3 port 0x4028 irq 96 uart 16950
/bin/setserial /dev/ttyS4 port 0x40A0 irq 104 uart 16950
/bin/setserial /dev/ttyS5 port 0x40A8 irq 104 uart 16950
Build instructions:
su root
cd
cc -o c c.c
ln -s c c0
ln -s c c1
ln -s c c2
Link to c for each serial port you have. For example c2 for ttyS2. Create an rc file for each of these. For example, this is for c2:
/root/.c2rc
port = "/dev/ttyS4"
baud = "9600"
flow = "rtscts"
off = "/root/power off 1"
on = "/root/power on 1"
The parameters available in the rc file as the same as the command line options, see below.
Just type:
./c /dev/ttyS2 --baud=19200
or:
./c /dev/ttyUSB0 --baud=9600
Included is a shell script to control a CPS Power string (uses 300 baud serial port):
power
--baud=9600 Set baud rate
--flow=none Set flow control: none, rtscts, or xonxoff
--stop=1 Set number of stop bits: 1 or 2
--bits=8 Set number of data bits: 6, 5, 7 or 8
--parity=none Set parity: none, even or odd
--hup=off Lower DTR on exit: on or off
--cd=off Exit if carrier detect goes low: on or off
--on='power on 1' Shell command to turn on power
--off='power off 1' Shell command to turn off power
--help Show this help
--send='foo' Send a string ot the serial port and exit
--noansi Suppress ANSI sequences
--hexdump Display received data in hexadecimal
Once connected, these ~ commands are available:
~b Send break
~q Exit
~h Show help
~f Turn machine off
~n Turn machine on
~!command Execute shell command
~<file Send a file
~<!command Send command output
~>file Log to a file
~> Close log file
~m Modify options (such as baud rate)
~o Show current options
~w Save current options as defaults
~s Print status information
~x Toggle hex-dump mode
~a Toggle no-ANSI mode