How to extract a value from a string using regex and a shell?

Question

I am in shell and I have this string: 12 BBQ ,45 rofl, 89 lol

Using the regexp: \\d+ (?=rofl), I want 45 as a result.

Answer 1

You can certainly extract that part of a string and that's a great way to parse out data. Regular expression syntax varies a lot so you need to reference the help file for the regex you're using. You might try a regular expression like:

[0-9]+ *[a-zA-Z]+,([0-9]+) *[a-zA-Z]+,[0-9]+ *[a-zA-Z]+

If your regex program can do string replacement then replace the entire string with the result you want and you can easily use that result.

You didn't mention if you're using bash or some other shell. That would help get better answers when asking for help.