vagrant ssh

vagrant ssh -c ""

vagrant ssh -c "screen -dmS rails -X stuff $'start_my_servern'"

vagrant » screen -dmS rails -p0 -X stuff $'start_my_servern'
There is a screen on:
    21810.rails (Detached)
No screen session found.

vagrant » screen -ls
There are screens on:
    21810.rails (Attached)
    18348.attacher  (Detached)
2 Sockets in /var/run/screen/S-vagrant.

vagrant ssh -c "screen -dmS rails -p0 -X stuff $'start_my_servern'"