Question

Is there any difference between enclosing grep patterns in single and double quotes?

grep "abc" file.txt

and

grep 'abc' file.txt

I’m asking since there’s no way I could test all possible cases on my own, and I don’t want to stumble into a case that I get wrong 🙂

Answer 1

I see a difference if you have special characters :

Ex :

grep "foo$barbase" file.txt

The shell will try to expand the variable $barbase, this is maybe not what you intended to do.

If instead you type

grep 'foo$barbase' file.txt

$bar is taken literally.

Finally, always prefer single quotes by default, it’s stronger.