new udev scripts to plug unplug a SmartLink USB soft modem

[golfer]

HOWTO use udev with linux-2.6.15+ to plug and play a SmartLink USB soft modem

The modem is a BestData SmartLink USB modem, and works with
slmodem-2.9.11-20051101.tar.gz from linmodems.org on Ubuntu testing
(dapper), which has linux-2.6.15 and udev-079.

lsusb reveals:

Bus 001 Device 002: ID 0483:7554 SGS Thomson Microelectronics 56k SoftModem

To get the plug and unplug action, create
/etc/udev/rules.d/10-slmodem.rules with this content:

BUS=="usb", SYSFS{idProduct}=="7554", SYSFS{idVendor}=="0483",
ACTION=="add", RUN+="/etc/init.d/slmodem-usb start", ENV{slmodem}="%p"
ACTION=="remove", ENV{slmodem}=="%p", RUN+="/etc/init.d/slmodem-usb stop"

To create/delete the /dev/slusb0 node, start/stop the daemon, and
create/delete a /dev/modem symlink, create /etc/init.d/slmodem-usb
with this content:

#!/bin/sh
#
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
test -x /usr/sbin/slmodemd || exit 0

start() {
    /sbin/modprobe slusb
        if ! [ -e /dev/slusb0 ]; then
          mknod /dev/slusb0 c 243 0
        fi
    echo -n "Starting SmartLink Modem driver for: slusb0"
    /sbin/start-stop-daemon --start --pidfile /var/run/slmodemd.pid
--exec /usr/sbin/slmodemd --make-pidfile --background --quiet -- -c
USA /dev/slusb0
    RETVAL=$?
    if [ "$RETVAL" = 0 ] ; then
        echo "Creating /dev/modem symlink, pointing to: /dev/ttySL0."
        ln -sf /dev/ttySL0 /dev/modem
    fi
}

stop() {
    echo -n "Shutting down SmartLink Modem driver normally"
    RETVAL=0
    if [ "`pidof slmodemd`" ] ; then
        if /sbin/start-stop-daemon --stop --quiet --pidfile
/var/run/slmodemd.pid --exec /usr/sbin/slmodemd --retry 1 ; then
            echo .
        else
            echo " probably failed."
            echo "Trying it the hard way (send SIGKILL all slmodemd
processes): "
            /usr/bin/killall -KILL slmodemd || RETVAL=1
        fi
    else
        echo " ... no slmodemd daemon running."
    fi
    if [ "$RETVAL" = 0 ] ; then
     rm -f "/var/run/slmodemd.pid"
     rm -f /dev/modem
     rm -f /dev/slusb0
     echo -n "Unloading modem driver from kernel ... "
     msg="none found."
        if grep -l -q slusb /proc/modules ; then
            /sbin/modprobe -r slusb 2>/dev/null && msg="slusb." || msg="failed."
        fi
     echo $msg
    fi
}

status() {
    echo -n "Status of SmartLink modem daemon: "
    if [ ! -r "/var/run/slmodemd.pid" ]; then
        echo "slmodemd is not running."
        exit 3
    fi
    if read pid < "/var/run/slmodemd.pid" && ps -p "$pid" > /dev/null 2>&1; then
        echo "slmodemd is running."
        exit 0
    else
        echo "slmodemd is not running but /var/run/slmodemd.pid exists."
        exit 1
    fi
}

# See how we were called.
case "$1" in
    start)
    start
    ;;
    stop)
    stop
    ;;
    restart)
    stop
    start
    ;;
    status)
    status
    ;;
    *)
    echo "Usage: /etc/init.d/slmodem-usb {start|stop|restart|status}"
    exit 1
esac