Regular Expressions 101

Negative Lookbehind(?<!\A)

\Astart of string

^start of line

Group 1(.*)

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

the literal (32₁₀ / 40₈ / 20₁₆)

\d{2}a Unicode decimal digit, repeated exactly 2 times

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{2}a Unicode decimal digit, repeated exactly 2 times

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{4}a Unicode decimal digit, repeated exactly 4 times

Positive Lookahead(?= +\d{2}:\d{2}:\d{2} *\r?\n(?! *\r?\n))

+the literal (32₁₀ / 40₈ / 20₁₆) , repeated at least once

\d{2}a Unicode decimal digit, repeated exactly 2 times

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\d{2}a Unicode decimal digit, repeated exactly 2 times

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\d{2}a Unicode decimal digit, repeated exactly 2 times

*the literal (32₁₀ / 40₈ / 20₁₆) , repeated any number of times

\r?optionally matches a carriage return (ASCII 13)

\na line-feed (newline) character (ASCII 10)

Negative Lookahead(?! *\r?\n)

*the literal (32₁₀ / 40₈ / 20₁₆) , repeated any number of times

\r?optionally matches a carriage return (ASCII 13)

\na line-feed (newline) character (ASCII 10)

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

No unit tests · Add a test to get started

Search reference

Regular Expression

(?<!\A)^(.*) \d{2}-\d{2}-\d{4}(?= +\d{2}:\d{2}:\d{2} *\r?\n(?! *\r?\n))

There are no unit tests, click to add some.