How to match only alphanumeric with regex

Question

I'm trying to match alphanumeric with the regex below, but still matched the result that I don't need.

([0-9a-z_]+|[0-9a-z]+)

What I really want to match are

Example:
abc123
abc_123

What I don't want to match are

Example:
abc
123
123_123
abc_abc

By alphanumeric do you mean that both numbers and letters should exist? This question is unclear. — revo, Sep 25 '18 at 08:50
Are these whole lines or do you plan to extract separate words with something like `grep -oE '...' file`? — Wiktor Stribiżew, Sep 25 '18 at 08:57
Try `\b_*([0-9]+_*[a-zA-Z]|[a-zA-Z]+_*[0-9])[[:alnum:]_]*\b` — Wiktor Stribiżew, Sep 25 '18 at 09:02

score -1 · Answer 1 · answered Sep 25 '18 at 15:25

-1

How about perl solution

> cat alphanum.txt
abc123
abc_123
abc
123
123_123
abc_abc
> perl -ne ' { print if /\b([a-z]+)|_\b/ and /([0-9]+)/ }' alphanum.txt
abc123
abc_123
>

try if this works for you.

answered Sep 25 '18 at 15:25

stack0114106

1 Answers1