You can type Ctrl + C to kill the process. Follow this link to see how it works
Ctrl+C is a map to the kill command. When you press them, kill sends a
SIGINT signal, that's interrupts the process.
You can also type another '
to "fix" your issue. Read this link to understand how quoting is treated in bash
Strong quoting
Strong quoting is very easy to explain:
Inside a single-quoted string nothing(!!!!) is interpreted, except the
single-quote that closes the quoting.
echo 'Your PATH is: $PATH' That $PATH won't be expanded, it's
interpreted as normal ordinary text, because it's surrounded by strong
quotes. In practise that means, to produce a text like Here's my
test… as a single-quoted string, you have to leave and re-enter the
single-quoting to get the character "'" as literal text: # WRONG echo
'Here's my test...'
RIGHT echo 'Here'\''s my test...'
ALTERNATIVE: It's also possible to mix-and-match quotes for readability: echo "Here's my test"