Regular Expressions 101

Positive Lookbehind(?<=\s|^)

1st Alternative\s

\sany whitespace character

2nd Alternative^

^start of line

Negated Character Class[^.\s]+

+matches at least one character outside the set below:

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\sany whitespace character

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Negated Character Class[^.\s]+

+matches at least one character outside the set below:

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\sany whitespace character

Positive Lookahead(?=@)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

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.

Search reference

Regular Expression

(?<=\s|^)[^.\s]+\.[^.\s]+(?=@)

New

blah blah blah test.this@gmail.com blah blah
blah blah blah test.this @gmail.com blah blah
blah blah blah test.this.this@gmail.com blah blah