$ adb shell screencap /sdcard/screen.png
$ adb shell screenrecord --verbose /sdcard/demo.mp4

# capture screen of android device
andrdroidScreenCapture() {
    curTime=`date +%Y-%m-%d-%H-%M-%S`
    tmpeName="$curTime.png"
    [[ -n $1 ]] && fileName=$1 || fileName=$tmpeName
    devicePath="/sdcard/$tmpeName"
    adb shell screencap -p $devicePath
    adb pull $devicePath $fileName
    adb shell rm $devicePath
}

export ADB_SHELL_SCREENRECORD_ARGS='--verbose --bit-rate 2000000'
# record screen of android device
androidScreenRecord() {
    echo -e "\033[1m(press Ctrl-C to stop recording)\033[0m"
    curTime=`date +%Y-%m-%d-%H-%M-%S`
    tmpeName="$curTime.mp4"
    [[ -n $1 ]] && fileName=$1 || fileName=$tmpeName
    devicePath="/sdcard/$tmpeName"
    adb shell screenrecord $ADB_SHELL_SCREENRECORD_ARGS $devicePath
    sleep 1 # wait for video encoding finish
    adb pull $devicePath $fileName
    # Don't delete copy in device.
    # adb shell rm $devicePath
    open $fileName
}

function asc() {
    if [[ -z $1 ]]; then
        echo "Please provide a filename."
        echo "Provideing .png extension for capturing the device screen, and providing .mp4 for recording the device screen."
        return
    fi
 
    if [[ $1 == *.png ]]; then
        andrdroidScreenCapture $1
    elif [[ $1 == *.mp4 ]]; then
        androidScreenRecord $1
    else
        echo "Filename with unknow extension, only .png and .mp4 are supported"
    fi
}