Sharing a GNU Screen Session

Inside your own screen session do the following (I am bob and want to share my screen with fred)

^A :multiuser on
^A :acladd fred

then tell fred to type:

$ screen -x bob/

screen has to be installed as suid root for this to work. (sudo chmod +s /usr/bin/screen, this could be a security risk)

there is more information about the acl-syntax on the screen man page - it is possible to share a screen session read only, for example

Good tutorial here. See this part of the GNU screen manual on how to set ACL permissions. Give him whatever permission you think he needs, though I don't think you'd need to change it from the default that's given by acladd.