dial.sh

#!/bin/sh
# This script is written by [email protected].
# Please, see `man 8 chat` for more info and
# http://tehm.info/modem_AT_command
# for AT commands description.

MODEM="cuau0"
TIMEOUT="30"

LOCKFILE="/var/spool/lock/LCK..${MODEM}"
PHONES="/etc/phones"

LOGGER="/usr/bin/logger -t dial"

COUNT="20"
PAUSE="10"
DIAL="0"

# Small description for shell running
echo "Please, see syslog messages for description"

# Have we got a username?
if [ -z $1 ]; then
    RESULT="Please, provide a username!";
    EXIT_CODE="1";
else
    # Get a phone number
    $LOGGER "Getting a phone number of user $1 from file $PHONES"
    NUMBER=`grep -w "$1" $PHONES | awk '{print $2}'`
        if [ x${NUMBER} = x"" ]; then
            RESULT="Can't find such username or it doesn't have a number";
            EXIT_CODE="1";
        else
            $LOGGER "Phone number is $NUMBER";

            # Don't give up for $COUNT times
            while [ $COUNT -gt 0 ] ; do

                # Check lock file
                if [ -f $LOCKFILE ]; then
                    PID=`cat "$LOCKFILE" | tr -d ' '`;
                    # Whether the process $PID is running?
                    RUN=`ps axopid -p $PID | grep -v PID | wc -l`;
                    if [ $RUN -eq 0 ]; then
                        $LOGGER "Stale lock on $MODEM PID=${PID}... overriding.";
                        DIAL="1";
                    else
                        $LOGGER "It's already locked by pid $PID. Waiting for $PAUSE seconds...";
                    fi
                else
                    DIAL="1";
                fi

                if [ $DIAL -eq 1 ]; then
                    $LOGGER "Making lock file...";
                    echo -e "\t$$" > $LOCKFILE;

                    # Let's dial
                    $LOGGER "Dialing..."
                    chat -t $TIMEOUT -e \
                        '' ATZ OK-ATZ-OK ATS7=0 OK \
                        ATDT"${NUMBER}" 'NO CARRIER' \
                        < /dev/${MODEM} 2>&1 > /dev/${MODEM} \
                        | grep -v '^$' | $LOGGER

                    # Delete lock file
                    rm "$LOCKFILE";
                    RESULT="Dial has been done!";
                    EXIT_CODE="0";
                    break;
                fi

                COUNT=$(($COUNT-1));
                sleep $PAUSE;

                if [ $COUNT -eq 0 ]; then
                    RESULT="Script has exhausted attempts!";
                    EXIT_CODE="1";
                fi

            done
        fi
fi

$LOGGER $RESULT;
exit $EXIT_CODE;