Shortcut to Drop Cache Linux on Zshell

.zshrc

# Press F5 on command line to drop cache
# Tested on Ubuntu 16
is_sudoed=false
eval "f5() {zle push-line;LBUFFER+='fkey_f5';zle accept-line}"
zle -N f5
bindkey '^[[15~' f5
function fkey_f5 {
    if [ "$is_sudoed" = 'true' ]; then
        sync | sudo tee /proc/sys/vm/drop_caches
    else
        sync && echo 'you_root_password_here' | sudo -S tee /proc/sys/vm/drop_caches
    fi
    is_sudoed=true
}