Access to serial port ttyS0

Dieter · 2011-01-01 21:58:49

Hello,

I'm trying to use a self-built mgetty+sendfax package (the one in AUR doesn't compile here) to access my modem on /dev/ttyS0 (to send faxes to DSL / VoIP). The mgetty+sendfax program "fax-helper" normally runs as user "fax" and tries to access ttyS0 as group "uucp". That worked some months ago, at that time /dev/ttyS0 had the following access rights:
crw-rw---- 1 root uucp 4, 64 1. Jan 21:56 /dev/ttyS0

But now the right to access ttyS0 is more restricive:
crw------- 1 root root 4, 64 1. Jan 21:56 /dev/ttyS0

The group changed from "uucp" to "root" only - and the fax-helper application of mgetty+sendfax can't access the port any more. Of course, faxing works when I manually change the group to "uucp" before sending the fax. After reboot, the access rights for /dev/ttyS0 then are again restrictive root.root.

What is the optimal solution for this issue?
a) Using hylafax instead of mgtetty+sendfax. I haven't tried hylafax yet, so I don't know whether hylafax solved the problem.
b) Setting up an udev rule to change the access rights for /dev/ttyS0. Will that work?
c) Use a fax service in the internet (that's not free of charge while for DSL / VoIP I have a flatrate).
d) Try to modify mgetty+sendfax to run the fax-helper application as root?

Your help will be appreciated.

cactus · 2011-01-01 23:11:11

(b) sounds like the best solution to me.

Google search result that seems reasonably close to what you need.
http://www.linuxquestions.org/questions … ce-644237/

Dieter · 2011-01-04 21:35:54

I got it. Successfully created working mgetty package and can submit faxes with it.
Thanks for your assistance!

Arch Linux

#1 2011-01-01 21:58:49

Access to serial port ttyS0

#2 2011-01-01 23:11:11

Re: Access to serial port ttyS0

#3 2011-01-04 21:35:54

Re: Access to serial port ttyS0

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