regex101: PCRE (Legacy) Match Workspace

Group tag(?<tag>(?&TAG))

(?&TAG)calls group TAG as a subroutine

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\s*any whitespace character, repeated any number of times

Group message(?<message>.*?)

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

Group 3( < (?<author>(?:\w{3}\s*,\s*)*\w{3})?\s* (?<date>(?&DATE))? (?<flags>(?&FLAGS))? > )?

?repeats the group contents below at most once:

< the literal text <

Group author(?<author>(?:\w{3}\s*,\s*)*\w{3})?

?repeats the group contents below at most once:

Non-Capturing Group(?:\w{3}\s*,\s*)*

*repeats the group contents below any number of times:

\w{3}any word character, repeated exactly 3 times

\s*any whitespace character, repeated any number of times

,the literal , (44₁₀ / 54₈ / 2C₁₆)

\s*any whitespace character, repeated any number of times

\w{3}any word character, repeated exactly 3 times

\s*any whitespace character, repeated any number of times

Group date(?<date>(?&DATE))?

?repeats the group contents below at most once:

(?&DATE)calls group DATE as a subroutine

Group flags(?<flags>(?&FLAGS))?

?repeats the group contents below at most once:

(?&FLAGS)calls group FLAGS as a subroutine

> the literal text >

$end of line

Definition Group(?(DEFINE) (?<TAG>\b(NOTE|LEGACY|HACK|TODO|FIXME|XXX|BUG)) (?<DATE>\d{4}-\d{2}-\d{2}) (?<FLAGS>[pts]:\w+\b) )

\ban ASCII word boundary

1st AlternativeNOTE

NOTEthe literal text NOTE (case sensitive)

2nd AlternativeLEGACY

LEGACYthe literal text LEGACY (case sensitive)

3rd AlternativeHACK

HACKthe literal text HACK (case sensitive)

4th AlternativeTODO

TODOthe literal text TODO (case sensitive)

5th AlternativeFIXME

FIXMEthe literal text FIXME (case sensitive)

6th AlternativeXXX

XXXthe literal text XXX (case sensitive)

7th AlternativeBUG

BUGthe literal text BUG (case sensitive)

Group DATE(?<DATE>\d{4}-\d{2}-\d{2})

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

Group FLAGS(?<FLAGS>[pts]:\w+\b)

Character Class[pts]

pthe literal p (112₁₀ / 160₈ / 70₁₆) (case sensitive)

tthe literal t (116₁₀ / 164₈ / 74₁₆) (case sensitive)

sthe literal s (115₁₀ / 163₈ / 73₁₆) (case sensitive)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\w+any word character, repeated at least once

\ban ASCII word boundary

Global pattern flags

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

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

Search reference

Regular Expression

(?<tag>(?&TAG)):\s*
(?<message>.*?)
(
<
   (?<author>(?:\w{3}\s*,\s*)*\w{3})?\s*
   (?<date>(?&DATE))?
   (?<flags>(?&FLAGS))?
>
)?
$

(?(DEFINE)
   (?<TAG>\b(NOTE|LEGACY|HACK|TODO|FIXME|XXX|BUG))
   (?<DATE>\d{4}-\d{2}-\d{2})
   (?<FLAGS>[pts]:\w+\b)
)

New

// NOTE: A small example
// HACK: Another example <ABC 2014-02-03>
// HACK: Another example <ABC,DEF 2014-02-03>
// HACK: Another example <ABC,DEF p:0>

Regular Expressions 101

Regular Expression

Extraction