[Bash script] How can I read a tty device?

[Magicloud Magiclouds]

Hi,

  Say I have device /dev/ttyACM0. If I `stty -F /dev/ttyACM0 raw`, then `cat /dev/ttyACM0` in one term, and `echo -e "QUERYCOMMAND" > /dev/ttyACM0` in another term. I would get the data in first term.

  But if echo first, then cat. The data seemed lost. Cat would not get anything. So I think these two commands must be run at the same time.

  So I put this process be in a script like this:

        (stty -F $tty raw

        currentSettings=""

        while [ 1 ]

        do

                c=`dd if=$tty count=1`

                currentSettings=${currentSettings}${c}

                if [ c == '.' ]

                then

                        break

                fi

        done

        echo -n $currentSettings > $conf) &

        echo -e "${query}?." > $tty

        until [ -e $conf ]

        do

                sleep 1

        done

        currentSettings=`cat $conf`

  The script stuck at dd, it did not get anything.

  What should I do?

--
竹密岂妨流水过
山高哪阻野云飞

And for G+, please use magiclouds#gmail.com.

[Magicloud Magiclouds]

Ah, I get it. 'read -n1' is the way.

[Jasper Noe]

You might be interested in a utility called 'chat', that is part of the
'ppp'-package.
It is meant for scripts like this.

HTH, --Jasper.


--
To UNSUBSCRIBE, email to debian-us...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listm...@lists.debian.org
Archive: http://lists.debian.org/519600...@xs4all.nl