#!/bin/sh
prog=`basename $0`
upTime=0
[ "$1" ] && {
  upMins=$1
  upTime=$(($1*60))
}
[ $upTime -gt 0 ] || { cat >&2 <<EOS
  bring up the ppp link for at most \$1 minutes to run specified command
  (remaining args are the command to run)
  if no command specified, defaults to sleep $1
  default link is drifter but this may be specified as via \$iface env variable

  examples:
    $prog 5  #bring up the drifter ppp link for 5 minutes
    $prog 10 update  #bring up link for at most 10 min to run update
EOS
exit 1
}

shift
[ "$1" ] || set -- sleep $upTime
: ${iface:=drifter}
while ! sudo /esp/call $iface; do
  echo "`date` -- call $iface failed, retrying after 20 seconds..."
  sleep 20
done
trap "hangup $iface; exit 2" HUP INT QUIT TERM
echo "`date` -- $iface link is up for $upMins minutes or until $@ finishes"
timeOut -t ${upTime} "$@"
hangup $iface