Script to toggle Mac OS X SOCKS proxy, and setup a SOCKS server with SSH

proxy-toggle.sh

#!/bin/sh

PROXY_INTERFACE="Wi-Fi"
PROXY_HOST=127.0.0.1
PROXY_PORT=1080

# A host where ssh can login without interaction, with a key-based
# authentication.
SOCKS_PROC_USER="username"
SOCKS_PROC_HOST="example.com"
SOCKS_PROC_IDENTITY="~/.ssh/id_rsa"

SOCKS_PROC_LOG=/tmp/ssh-socks-proxy-log.txt
SOCKS_PROC_PIDFILE=/tmp/ssh-socks-proxy-pid.txt

SOCKS_PROC_CMD="ssh -i $SOCKS_PROC_IDENTITY -t -t -D $PROXY_HOST:$PROXY_PORT $SOCKS_PROC_USER@$SOCKS_PROC_HOST"

if [[ $1 == "on" ]]; then
    nohup $SOCKS_PROC_CMD > "$SOCKS_PROC_LOG" 2>&1 &
    echo $! > "$SOCKS_PROC_PIDFILE"

    sudo networksetup -setsocksfirewallproxy "$PROXY_INTERFACE" $PROXY_HOST $PROXY_PORT
    echo "SOCKS proxy enabled"

elif [[ $1 == "off" ]]; then
    sudo kill -9 $(cat "$SOCKS_PROC_PIDFILE")
    rm "$SOCKS_PROC_PIDFILE"

    sudo networksetup -setsocksfirewallproxystate "$PROXY_INTERFACE" off
    echo "SOCKS proxy disabled"

elif [[ $1 == "status" ]]; then
    echo "======================================================"
    echo "Network Services:"
    echo "======================================================"
    networksetup -listallnetworkservices
    echo
    echo "======================================================"
    echo "Current SOCKS Proxy Settings:"
    echo "======================================================"
    networksetup -getsocksfirewallproxy "$PROXY_INTERFACE"
    echo

else
    echo "`basename $0` toggles SOCKS proxy settings on OS X"
    echo
    echo "Usage: "
    echo "  $ proxy on           # turns SOCKS proxy on"
    echo "  $ proxy off          # turns SOCKS proxy off"
    echo "  $ proxy status       # prints status of proxy settings"
    echo
    echo "proxy interface:      " $PROXY_INTERFACE
    echo "proxy host:           " $PROXY_HOST
    echo "proxy port:           " $PROXY_PORT
    echo
    exit 65 # end process with error to indicate incorrect arguments
fi