regex101: PCRE2 (PHP) Substitution Workspace

Explanation

Pro

^start of line

Negative Lookbehind(?<![\s\S\r])

Character Class[\s\S\r]

\sany whitespace character

\Sany non-whitespace character

\ra carriage return (ASCII 13)

Group 1(---\ntitle:\s)

---the literal text ---

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

title:the literal text title: (case sensitive)

\sany whitespace character

Group 2([1-9a-zA-ZÀ-ŰØ-űø-ÿ].*)

Character Class[1-9a-zA-ZÀ-ŰØ-űø-ÿ]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

À-Űone character from À (192₁₀) to Ű (368₁₀) (case sensitive)

Ø-űone character from Ø (216₁₀) to ű (369₁₀) (case sensitive)

ø-ÿone character from ø (248₁₀) to ÿ (255₁₀) (case sensitive)

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

Group 3([\d\D]*---\n\n#\s[1-9a-zA-ZÀ-ŰØ-űø-ÿ].*)

Character Class[\d\D]*

*matches any number of characters from the set below:

\da digit

\Dany character that's not a digit

---the literal text ---

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

#the literal # (35₁₀ / 43₈ / 23₁₆)

\sany whitespace character

Character Class[1-9a-zA-ZÀ-ŰØ-űø-ÿ]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

À-Űone character from À (192₁₀) to Ű (368₁₀) (case sensitive)

Ø-űone character from Ø (216₁₀) to ű (369₁₀) (case sensitive)

ø-ÿone character from ø (248₁₀) to ÿ (255₁₀) (case sensitive)

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

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

Quick Reference

25 tokens

Regular Expression

^(?<![\s\S\r])(---\ntitle:\s)([1-9a-zA-ZÀ-ŰØ-űø-ÿ].*)([\d\D]*---\n\n#\s[1-9a-zA-ZÀ-ŰØ-űø-ÿ].*)

New

---
title: Title can be anything
aliases:
  - somealias
tags:
  - sometag
topic: sometopic
anotheryamlKey: whatever
date created: 2022-12-14
date modified: 2023-10-06
---

# Title can be anything

First line of file.  
Second line.

Extraction

---
title: Title can be anything
aliases:
  - somealias
tags:
  - sometag
topic: sometopic
anotheryamlKey: whatever
date created: 2022-12-14
date modified: 2023-10-06
---

# Title can be anything

First line of file.  
Second line.