copy_img_to_usb(){
    if [[ $1 = "" ]]
    then
        return 1
    fi
    FILE=$1
    FILESIZE=$(stat -c%s  "$1")
    TARGET=$2
    lsblk
    echo "Are you sure you want to copy $FILE to $TARGET?"
    read
    if [[ $REPLY =~ ^[Yy]$ ]]
    then
        sudo umount $TARGET?*
        dd bs=4M if=$FILE | pv -s $FILESIZE | sudo dd of=$TARGET conv=fsync
    fi
}

cdtemp(){
    local tmpfolder=$(mktemp -d)
    cd $tmpfolder
    aliasstring="change_dir $tmpfolder "
    #delete folder if cd out of it
    alias cd=$aliasstring
}

#belongs to the cdtemp function
change_dir(){
    #If no dir is specified go to home directory as expected
    if [[ $2 = "" ]]
    then
        cd
    else
        cd "$2"
    fi
    if [ ! $(expr match $(pwd) '\(/tmp/tmp.[a-zA-Z0-9]*\)') ]
    then
        echo "Deleting tmp folder $1."
        rm -rf "$1"
        unalias cd
    fi
}