Configure SSH and WiFi on a newly flashed Rasbpian SD card

rasbpian-configure.sh

#!/bin/bash
# Quickly enable SSH and configure WiFi settings on a newly flashed Rasbpian SD card.
# Note: this script is meant to be run from the machine used to flash the SD card, not from the Raspberry Pi!

# Run script without downloading (Windows users will need either git-bash or cygwin):
# bash <(curl -s https://gist.githubusercontent.com/martinharding/f86d44067adff7352f3d8091cf1b666c/raw/rasbpian-configure.sh)

# Determine SD card mount point
case $OSTYPE in
    msys | cygwin )
        SD_CARD_DEFAULT_MOUNT="D:"
        SD_CARD_MOUNT_MESSAGE="SD card drive letter (default '$SD_CARD_DEFAULT_MOUNT'): "
    ;;
    *)
        SD_CARD_DEFAULT_MOUNT="/Volumes/boot"
        SD_CARD_MOUNT_MESSAGE="SD card mount path (default '$SD_CARD_DEFAULT_MOUNT'): "
    ;;
esac

# Ask for SD Card mount point
read -p "$SD_CARD_MOUNT_MESSAGE" SD_CARD_MOUNT
SD_CARD_MOUNT=${SD_CARD_MOUNT:-$SD_CARD_DEFAULT_MOUNT}

# Error checking
if [ ! -d $SD_CARD_MOUNT/ ]; then
    echo "Error: '$SD_CARD_MOUNT' doesn't exist! Is the SD card mounted?"
    exit 1
fi

if [ ! -f $SD_CARD_MOUNT/cmdline.txt ] || [[ -z `cat D:/cmdline.txt | grep raspi` ]]; then
    echo "Error: '$SD_CARD_MOUNT' doesn't look like a Rasbpian boot partition. Double check the mount path entered."
    exit 1
fi

echo ""

# Enable SSH
# https://www.raspberrypi.org/documentation/remote-access/ssh/
SSH_ENABLE_PATH=$SD_CARD_MOUNT/ssh
if [ -f $SSH_ENABLE_PATH ]; then
    echo "SSH already enabled."
else
    echo "Enabling SSH"
    touch $SSH_ENABLE_PATH
    if [ $? == 0 ]; then
        echo "Created '$SSH_ENABLE_PATH'"
    else
        echo "Could not create '$SSH_ENABLE_PATH'; is the SD card mounted to $SD_CARD_MOUNT?"
        exit 1
    fi
fi

echo ""

# Setup WiFi
WPA_SUPPLICANT_PATH=$SD_CARD_MOUNT/wpa_supplicant.conf

function setupwifi {
    echo "Setting up WiFi"
    read -p "Enter network SSID: " WIFI_SSID
    read -s -p "Enter network Password: " WIFI_PSK

    # https://raspberrypi.stackexchange.com/questions/10251/prepare-sd-card-for-wifi-on-headless-pi
    echo "ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
    ssid=\"$WIFI_SSID\"
    psk=\"$WIFI_PSK\"
    key_mgmt=WPA-PSK
}" > $WPA_SUPPLICANT_PATH

    if [ $? == 0 ]; then
        echo -e "\nCreated $WPA_SUPPLICANT_PATH"
    else
        echo "Error: Could not create $WPA_SUPPLICANT_PATH; is the SD card mounted to $SD_CARD_MOUNT?"
        exit 1
    fi
}

if [ -f $WPA_SUPPLICANT_PATH ]; then
    echo "WiFi already enabled using:"
    SSID=`cat $WPA_SUPPLICANT_PATH | grep ssid | cut -d= -f2 | tr -d '\n'`
    echo "Network: ${SSID:1:${#SSID}-2}"
    PSK=`cat $WPA_SUPPLICANT_PATH | grep psk= | cut -d= -f2 | tr -d '\n'`

    echo "Password: `printf "%0.s*" $(seq 1 $((${#PSK}-5))); echo ${PSK:1:${#PSK}-2} | tail -c5`"

    while true; do
        read -p "Overwrite existing settings (y/n)? " choice
        case "$choice" in
            y|Y ) setupwifi; break;;
            n|N ) echo "Using existing WiFi settings."; break;;
            * ) echo "Please enter y or n.";;
        esac
    done
else
    setupwifi
fi

echo -e "\nSetup complete. Don't forget to change the SSH password!"