Want to use Null modem but can't find cu

Trac3R · 2008-04-07 11:50:19

Hello,

To connect two computers via crossed serial cable (Null modem), other Unixes have the tip and cu command. I learned that for Linux cu also exists but I can't find it in Arch repositories. I also looked for an uucp package (like with RedHat), but this doesn't exist either. So what package do I have to install?

BTW: Is there a HowTo for Null modems in Arch Wiki? Couldn't find any.

Bye

damjan · 2008-04-07 13:45:29

I was looking for it one time too.

You could use minicom or you can use [url href=http://www.comptechdoc.org/os/linux/programming/c/linux_pgcserial.html]com.c[/url].

Minicom is more featurefull, supporting ymodem etc, so you can transfer files too.

BTW if you need to setup TCP/IP then you should use pppd.

Something like:

pppd /dev/tts/0 115200 10.1.1.1:10.2.2.2 noauth passive crtscts # on one side

pppd /dev/tts/0 115200 noauth crtscts # on the other side

Trac3R · 2008-04-07 15:30:22

Well, pppd is no option at all, since I want to use the serial connection as a fallback system if ethernet i.e. sshd or something else is down. And as far as I can see I would have to login into the other side first or run a daemon. This wouldn't work.

This com.c file is called a "serial port test program" on that website. What means "test" here? See if it's up? And what next? It sends keyboard input but I don't see further info.

Minicom is window based... Mmh, I give it a try. But I really wonder why there's no cu.

Thanks for help, though.

Last edited by Trac3R (2008-04-07 15:34:21)

damjan · 2008-04-07 16:36:19

Well if you have agetty started on the serial port you can connect to it

Trac3R · 2008-04-07 22:55:38

Started where?

Something like this?
The headless remote system is a FreeBSD box and as far as I know it is listening on the serial ports by default and there's no more config needed. All I need is a tool to access it. Minicom hasn't convinced me. To be honest, I don't know how to use it with a Null modem. It always wants to dial up to a modem that doesn't exist. I'm to stupid for this. It gives me no errors, just this window. And the man page isn't helpful when it comes to setup options.

Or do you mean I can have a virtual console on my Arch box that shows me the login prompt of the other system, only by editing inittab?
How? agetty manpage says nothing about that. (btw inittab manpage is about System V, not BSD boot process)

s0:2345:respawn:/sbin/agetty -L 9600 ttyS0 vt100

Would listen passively, not connect. It works pretty nice from the other side, because FreeBSD has also cu installed by default. But that is not the direction I wanted, of course.

I'm not sure about it, but what would

c6:2345:respawn:/sbin/agetty -L 9600 vc/6 ttyS0

do? Set vc/6 listening on ttyS0?

Trac3R · 2008-04-09 00:44:28

Since there is no UUCP package in the repos, I decided to took directly GNU's version. Guess what, it works now.

Bye

Sigi · 2009-01-25 00:17:47

yay, someone built an AUR package for that one

fukawi2 · 2009-01-26 22:46:17

FTR, uucp is in the AUR... I've been using it for a while:

 $ yaourt uucp
1 aur/uucp 1.07-1 (11)
    Taylor UUCP is a free implementation of UUCP and is the standard UUCP used on the GNU system

Sigi · 2009-01-26 23:28:01

That's the one I was referring to, exactly

Arch Linux

#1 2008-04-07 11:50:19

Want to use Null modem but can't find cu

#2 2008-04-07 13:45:29

Re: Want to use Null modem but can't find cu

#3 2008-04-07 15:30:22

Re: Want to use Null modem but can't find cu

#4 2008-04-07 16:36:19

Re: Want to use Null modem but can't find cu

#5 2008-04-07 22:55:38

Re: Want to use Null modem but can't find cu

#6 2008-04-09 00:44:28

Re: Want to use Null modem but can't find cu

#7 2009-01-25 00:17:47

Re: Want to use Null modem but can't find cu

#8 2009-01-26 22:46:17

Re: Want to use Null modem but can't find cu

#9 2009-01-26 23:28:01

Re: Want to use Null modem but can't find cu

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