Quote from the software library attributable to Michael A Jackson?

While discussing modular software, a colleague recently suggested that the following quote (or similar words) is attributable to computer scientist Michael A Jackson. However, I can not find any reference to him on the Internet and I was wondering if anyone could point me to any of Jackson's works that contain it.

A library of software modules is the only type of library in which
Everyone wants to put something, and nobody wants to take something.
outside.

mysql – How to escape from a single quote within a string of double quotes in the bash script?

I am trying to execute the following bash code:

#! / bin / bash
export DEBIAN_FRONTEND = non-interactive

DB_USER = & # 39; abc & # 39;
DB_USER_PASSWORD = & # 39; 123 & # 39;
DB_MAGENTO = & # 39; db_magento & # 39;

sudo apt-get update
echo debconf mysql-server / root_password password $ DB_USER_PASSWORD | sudo debconf-set-selections
echo debconf mysql-server / root_password_again password $ DB_USER_PASSWORD | sudo debconf-set-selections
sudo apt-get -qq install mysql-server> / dev / null # Install MySQL silently
sudo mysql -uroot -p123 -e "CREATE SCHEMA $ {DB_MAGENTO} CONFIGURATION OF DEFAULT CHARACTERS utf8; SHOW DATABASES; * TO  & # 39; $ {DB_USER}  & # 39; @ & # 39; localhost & # 39 ;; FLUSH PRIVILEGES; SELECT Host, User, Password FROM mysql.user; "

The error that I am receiving is ERROR on line 1: unknown command & # 39; & # 39; & # 39;
It seems to be related to & # 39; $ {DB_USER} & # 39; .

How to escape from these simple quotes correctly?

Magento1 Add new comuns in the quote table

I have added 4 new columns of product attributes in my sales_flat_quote_item now if I add product, the value in this column will be according to the attribute of the product, how I achieve that with good code practice.

magento2 – quote getAllItems returns an empty array

    public function getItems () {
$ a = array ();
$ customerId = null;
$ userType = GroupInterface :: NOT_LOGGED_IN_ID;
$ isGuest = true;
$ quote = null;
if ($ this-> isLoggedIn ()) {
$ customerId = $ this-> userContext-> getUserId ();
$ isGuest = false;
$ quote = $ this-> cartObj-> getQuote () -> loadByCustomer ($ customerId);

}
plus{
$ quote = $ this-> cartObj-> getQuote ();
$ quote-> setCustomerGroupId (GroupInterface :: NOT_LOGGED_IN_ID);
}
$ quote-> setCustomerIsGuest ($ isGuest);
$ items = $ quote-> getAllItems ();
foreach ($ items as $ item) {
array_push ($ a, $ item-> getData ());
/ * $ a[$i]['ProductId']    = $ item-> getProductId (); * /
}
// array_push ($ a, $ items);
returns $ a;
}

this code returns the empty result, even the cart is not empty and when I call

        $ quote-> getItemsCount ();

it gives me back 4

Why does this happen

Magento2 removes all discounts from the quote

I want to remove all the coupons from qoute.
basically it can be achieved by

$ this-> checkoutSession-> getQuote () -> setCouponCode (& # 39; & # 39;) -> collectTotals () -> save ();

But right now I have set the categorywise discount coupon code. Not necessary, then, how can I delete it?
I tried this but it did not work too

foreach ($ quote-> getAllVisibleItems () as $ item)
{
$ item = $ quote-> getItemById ($ item-> getId ());
$ item-> setNoDiscount (true);
$ item-> setDiscountAmount (null) -> setBaseDiscountAmount (null);
$ item-> getProduct () -> setIsSuperMode (true);
$ item-> save ();
}
$ this-> quoteRepository-> save ($ quote);

Error with the software updater: "E: The repository & # 39; http: //ppa.launchpad.net/clipgrab-team/ppa/ubuntu cosmic version & # 39; does not have a version file".

E: The repository & # 39; http: //ppa.launchpad.net/clipgrab-team/ppa/ubuntu cosmic version & # 39; It does not have a version file.