ADB Take Screenshot and Pull It

AndroidScreenshot.sh

#!/usr/bin/env bash

set -euo pipefail
IFS=$'\n\t'

function usage(){
    echo -e "\nThis script will screenshot what is happening on an Android device"
    echo -e " "
    echo -e "Usage: './`basename $0` foo' or './`basename $0` foo.mp4'"
    echo -e "Both of the above will produce a recording with the filename 'foo.mp4'"
    echo -e "\n*** Optional Parameters ***\n"
    echo -e "-h | --help \t\t\t Show this help!"
    echo -e " "
    exit 1
}

function checkIfFileExists(){
    if [ -f ${FILENAME} ]; then
        echo "[ERROR] The recording you are trying to create already exists!"
        read -r -p "Do you want to overwrite this file? [y/N] " RESPONSE
        RESPONSE=`echo ${RESPONSE}| awk '{print tolower($0)}'`
        if [[ (${RESPONSE} == "" || ${RESPONSE} == "n" || ${RESPONSE} == "no") ]];then
            exit 1
        fi
    fi
}

function takeScreenshot(){
	echo "Taking screenshot '${FILENAME}'..."
    adb shell screencap -p /sdcard/${FILENAME}

	echo "Process complete."
}

function pullScreenshot(){
    echo "Downloading screenshot '${FILENAME}'..."
    adb pull /sdcard/${FILENAME}

    echo "Process complete."
}

function deleteScreenshotFromDevice(){
    echo "Deleting screenshot '${FILENAME}'..."
    adb shell rm /sdcard/${FILENAME}

    echo "Process complete."
    exit 0
}

[[ $# -eq 1 ]] || { usage; }

for _ARGUMENT in "$@"
do
    case ${_ARGUMENT} in
        -h|--help)
        usage
        ;;
        *)
        if [[ ! ${_ARGUMENT} =~ ^.*png$ ]]; then
            FILENAME="${_ARGUMENT}.png"
        else
            FILENAME="${_ARGUMENT}"
        fi
        ;;
    esac
done

checkIfFileExists
takeScreenshot
pullScreenshot
deleteScreenshotFromDevice