zsh/bash "command not found" handler that will use ssh if $1 resolves

try_connect_ssh.sh

#
#                         _______
#   ____________ _______ _\__   /_________       ___  _____
#  |    _   _   \   _   |   ____\   _    /      |   |/  _  \
#  |    /   /   /   /   |  |     |  /___/   _   |   |   /  /
#  |___/___/   /___/____|________|___   |  |_|  |___|_____/
#          \__/                     |___|
#
#
# Put this in your ~/.zshrc or ~/.bashrc:
#   source ~/.zsh/ssh
#
# (c) 2011 Wijnand Modderman-Lenstra <maze@pyth0n.org>
# MIT License
#

is_ip() {
    IP="$1"
    python - "${IP}" <<EOF
import socket
import sys 
# Check IPv6
if socket.has_ipv6:
    try:
        socket.inet_pton(socket.AF_INET6, sys.argv[1])
        sys.exit(0)
    except socket.error:
        pass
# Check IPv4
try:
    socket.inet_pton(socket.AF_INET, sys.argv[1])
    sys.exit(0)
except socket.error:
    sys.exit(1)
EOF
    return $?
}

try_connect_ssh() {
    # If only one argument is supplied and $1 resolves into a hostname,
    # connect there using ssh 
    if [[ $# -gt 0 ]]; then
        RESOLVES=$(host -W 2 $1 2>/dev/null | grep -v NXDOMAIN)
        if [ -z "${RESOLVES}" ]; then
            if is_ip "$1"; then
                RESOLVES="$1"
            fi  
        fi  
        if [ $? -eq 0 -a -n "${RESOLVES}" ]; then
            ssh "$@"
            # Tell zsh we did handle the command
            return 0
        fi  
    fi  
.
    # Tell zsh we didn't handle the command
    return 1
}

case "${SHELL}" in
    */zsh)
        command_not_found_handler() {
            try_connect_ssh "$@"
            return $?
        }   
        ;;  
    */bash)
        command_not_found_handle() {
            try_connect_ssh "$@"
            return $?
        }   
        ;;  
esac

Updated the file so you can also use stuff like:

shell% <hostname> -l root

Updated the file so that you can also use IP addresses:

shell% 127.0.0.1
Password: