request specific port

src/ssh-backdoor-open

@@ -13,6 +13,7 @@ if [[ "$1" = update ]]; then
 fi
 
 _ssh() {
+  trap 'kill -INT -$sshpid; exit;' INT
   timeout -k 10 3700 ssh \
        -o UserKnownHostsFile=/dev/null \
        -o StrictHostKeyChecking=no \
@@ -21,15 +22,16 @@ _ssh() {
        -o ServerAliveCountMax=3 \
        -p ${BACKDOORPORT} \
        ${BACKDOORHOST} \
-       "$@"
+       "$@" &
+  sshpid=$!
+  wait $sshpid
        #~ -o "ExitOnForwardFailure yes" \
 }
 
 BACKDOORHOST={{BACKDOORHOST}}
 BACKDOORPORT={{BACKDOORPORT}}
 USER=$( id -u -n )
-echo use of ssh-add is encouraged
-( sleep 3; printf "%d\r" $SECONDS ) &
+echo "Must use ssh agent (ssh-add)"
 while true; do
     port=$( _ssh bin/ssh-backdoor open $USER@$HOSTNAME )
     [[ -z "$port" ]] && { sleep 2; continue; }
@@ -47,4 +49,3 @@ while true; do
        printf "      $i\r"
     done
 done
-kill %1