regex: strings with a point in the middle

Question

im having a hardtime with this regex, i need to validate two words with a required point between them, no special characters, no @, no spaces, just the words and the point in the middle. for example:

test.test

i have been trying with this one, however it doesnt work:

^[a-z']*.[a-z']+$

can someone please help me with this? i have been stucked for a while now, thanks in advance

I wouldn't define `test.test` as a "two letters string". Do you want a string with letter.letter (`a.a`) or word.word (`something.something`). — Balastrong, Jun 19 '20 at 16:48
thats exactly what i needed, thanks!!! how can i vote the right answer? @anubhava — Solar Confinement, Jun 19 '20 at 16:52
Depending on where you are running your regex you need to escape the right characters. You certainly need to escape the dot. If you are running on a linux shell (e.g.: `echo "aaa" | grep "a\+"`), with many basic commands you have to escape the + character as well. Some later or advanced commands (like egrep) don't need that. Be sure you figure out what needs to be escaped in your environment. — Uluaiv, Jun 19 '20 at 16:56
You may accept answer by @dang as he was the first one to post an answer. — anubhava, Jun 19 '20 at 16:59

score 2 · Accepted Answer · edited Jun 19 '20 at 17:00

2

The dot is the wildcard operator, it must be escaped with a backslash, \.

This Wiki on Regex contains info about the wildcard and other common characters for RegEx under "Basic Concepts"

edited Jun 19 '20 at 17:00

JvdV

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answered Jun 19 '20 at 16:49

dang

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score 2 · Answer 2 · answered Jun 19 '20 at 16:52

Escape the dot with slash to make it literal dot otherwise it will match any character

^[a-z']+\.[a-z']+$

In regular expressions, the dot (.) is a special character used to match any one character.

Use the backslash to escape any special character and interpret it literally; for example:

\\ (escapes the backslash)
\[ (escapes the bracket)
\{ (escapes the curly brace)
\. (escapes the dot)

regex: strings with a point in the middle

2 Answers2