Objective

The next challenge uses getchar$()$ to get user input and make selections from a menu.

getchar$()$ Info

The getchar$()$ function gets a single character from standard input.

It returns an unsigned char $($or in most instances basically a char$)$ containing the entered value.

NOTE: If the user input is terminated with an enter, the enter gets caught in the buffer. So$,$ it is necessary to follow up the getchar$()$ with another to clear the enter out of the buffer.

Steps to Complete

Modify the provided code according to the CODE: comments

Write a user test $4\mathrm{.}1$ that tests the insert function call

Write a user test $4\mathrm{.}2$ that tests for "Error entry not in the list" when an invalid choice is made

Run $/$challenge$/$tester and get your flag.

HINT: If the code relies on a switch statement, the options. Then for $0$ it will need separate functionality to exit the loop, an if $($ch$==\text{'}0\text{'})$ after the switch will work. This is necessary because a break from inside the switch is absorbed by it and does not exit the loop.