screen-agent-fix.sh

#!/bin/sh

capture () {
  echo $SSH_AUTH_SOCK > /tmp/$(whoami)-auth-sock-path
}

clean () {
  rm /tmp/$(whoami)-auth-sock-path
}

apply () {
  mkdir -p $(dirname $SSH_AUTH_SOCK)
  ln -sf $(cat /tmp/$(whoami)-auth-sock-path) $SSH_AUTH_SOCK
  clean
}

$1

screen-ssh-agent-fix

SSH Agent Forwarding Abusive Trickery
Useful in screen sessions when your SSH connection is lost. When you connect again, you end up with a new SSH agent socket ($SSH_AUTH_SOCK), but when you reconnect to screen, the value of $SSH_AUTH_SOCK will remain unchanged and your agent forwarding will be broken.

# The proper, somewhat irritating solution

1. `echo $SSH_AUTH_SOCK' OUTSIDE screen and copy its result
2. Attach to your screen session and hit Ctrl-A+:. Type `setenv SSH_AUTH_SOCK $(value of SSH_AUTH_SOCK from outside)`
3. Either close and reopen every window in screen or execute `export SSH_AUTH_SOCK=$(value of SSH_AUTH_SOCK from outside)' or similar in every terminal you'll be using SSH in. Note: this sucks.

# The cheap, lazy solution

1. `echo $SSH_AUTH_SOCK > /tmp/$(whoami)-auth-sock-path` outside screen
2. Inside screen, open a terminal. `mkdir $(dirname $SSH_AUTH_SOCK); ln -sf $(cat /tmp/$(whoami)-auth-sock-path) $SSH_AUTH_SOCK; rm /tmp/$(whoami)-auth-sock-path`

# The incredibly lazy solution

Grab the screen-agent-fix script attached, put it in your $PATH, and run it like this:

1. `screen-agent-fix.sh capture' OUTSIDE
2. `screen-agent-fix.sh apply' INSIDE