Regular Expressions 101

Pro

1st Alternative(?:^|@).\K

Non-Capturing Group(?:^|@)

1st Alternative^

^start of line

2nd Alternative@

@the literal @ (64₁₀ / 100₈ / 40₁₆)

.any character (except for line terminators)

\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match

2nd Alternative\.[^@]*$(*SKIP)(*F)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Negated Character Class[^@]*

*matches any number of characters outside the set below:

@the literal @ (64₁₀ / 100₈ / 40₁₆)

$end of line

(*SKIP)acts like (*PRUNE), but the next unanchored match attempt starts where (*SKIP) was reached instead of at the next subject character

(*F)forces the current match attempt to fail at this position

3rd Alternative.(?=.*?\.)

.any character (except for line terminators)

Positive Lookahead(?=.*?\.)

.*?any character (except for line terminators), repeated any number of times

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

25 tokens

(?:^|@).\K|\.[^@]*$(*SKIP)(*F)|.(?=.*?\.)

New

great@gmail.com
myemail@gmail.co.uk
test.test@gmail.com
test.test@gmail.co.uk

*

great@gmail.com
myemail@gmail.co.uk
test.test@gmail.com
test.test@gmail.co.uk