SSH Remote Forwarded Clipboard

cb.sh

##
# SSH Remote Forwarded Clipboard
#
# Advantages
#   You can copy stuff on a remote machine to your local clipboard (e.g. you could use the script in a shell theme)
#   It is not intended to do it the other way round (makes no sense since you usually will use your local clipboard)
#
# Security Concerns
#   Someone else on the remote host could spam or exploit your clipboard exploit it (xsel, xclipbaord, parcellite etc.)
#
# Requiremnts:
#   xsel has to be present (package xsel on most systems)
#   functions of this script added to your favorite shell
#   Your SSH config should look like:
#     Host *
#       RemoteForward 8787 localhost:8787
#



##
# Remote Forward Clipboard Wrapper for Pasting to SSH Client via port 8787
# - put this function in local rc file
# - put this function in remote rc file
#
# Uses nc, local-file cache and &>/dev/tcp/127.0.0.1/8787 as fallback
#
cb() {
	local clipFile
	local isRemote=0
	local buffer=""
	if [[ -n "${SSH_CONNECTION:-}" ]]; then
		clipFile="/tmp/clip-$(echo -n ${SSH_CONNECTION%% *})"
		isRemote=1
	fi

	if [ ! -t 0 ]; then
		# copy
    	IFS= buffer="$(cat /dev/stdin)"
    	if [[ "$isRemote" -eq 1 ]] || ! xset q &>/dev/null; then
    		IFS= command echo -n "$buffer" > "$clipFile"
    		if [[ "$isRemote" -eq 1 ]]; then
	    		if which nc 1>/dev/null 2>&1; then
	    			IFS= command echo -n "$buffer" |  nc localhost 8787
	    		else
	    			IFS= command echo -n $buffer &>/dev/tcp/127.0.0.1/8787
	    		fi
    		fi
    	elif which xsel 1>/dev/null 2>&1; then
    		IFS= command echo -n "$buffer" | xsel -ib
    	elif which xclip 1>/dev/null 2>&1; then
    		IFS= command echo -n "$buffer" | xclip -selection c
    	fi
	else
		if [[ "$isRemote" -eq 1 ]] || ! xset q &>/dev/null; then
    		command cat "$clipFile"
    	elif which xsel 1>/dev/null 2>&1; then
    		xsel -ob
		elif which xclip 1>/dev/null 2>&1; then
    		xclip -selection c -o
    	fi
	fi
}

##
# Clipboard server for our X-Desktop
# - put this function in local rc file
#
# Just listens to port 8787 on localhost and forwards everything to your system clipboard
#
cb-server() {
	while :; do nc localhost -l 8787 | cb || break; done;
}

##
# SSH Wrapper function to ensure clipboard-server is running
# - put this function in local rc file
#
# Note: Some ZSH config may leave jobs running in background!
# - use &! to disown and run forever
# - http://zsh.sourceforge.net/Doc/Release/Options.html#Description-of-Options
ssh() {
	local opts=()
	if [[ -n "${ZSH_VERSION:-}" ]]; then
		opts=($(setopt))
		setopt nonotify nomonitor
	fi
	cb-server 1>/dev/null 2>&1 & 
	sleep 0.1
	if [[ -n "${ZSH_VERSION:-}" ]]; then
		setopt "${opts[@]}"
	fi
	command ssh "$@"
	# cb-server will run as long a shell is active
}