Download a new version of flashplayer and move it in mozilla dir.

update_mozilla_flashplayer.sh

#!/bin/bash

set -a
player="libflashplayer.so"
work_dir="/tmp/flash_update"
mozilla_dir="$HOME/.mozilla/plugins"

download_player() {
    tarball="install_flash_player_11_linux.x86_64.tar.gz"
    wget -nc "https://fpdownload.macromedia.com/get/flashplayer/current/licensing/linux/$tarball"
    tar -xzf $tarball
}

get_cksum() {
    cksum $1 | cut -d " " -f1 
}

mkdir -p $work_dir
cd $work_dir
download_player
new_player=$player
new_player_cksum=`get_cksum $new_player`
old_player="$mozilla_dir/$player"

if [ -f $old_player ]; then
    old_player_cksum=`get_cksum $old_player`
else
    old_player_cksum="0"
fi

if [ $old_player_cksum -eq $new_player_cksum ]; then
    echo "Sums are the same, so nothing to update"
    cd ../
    rm -fr $work_dir
else
    mkdir -p "$mozilla_dir"
    cp "$new_player" "$old_player"
    echo "$player updated"
fi