Regular Expressions 101

^start of line

PAT_A_the literal text PAT_A_ (case sensitive)

Negated Character Class[^;\n]*

*matches any number of characters outside the set below:

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

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

Non-Capturing Group(?:\n(?![^\n;]*NOT_MATCH_THIS)[^;\n]*)*

*repeats the group contents below any number of times:

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

Negative Lookahead(?![^\n;]*NOT_MATCH_THIS)

Negated Character Class[^\n;]*

*matches any number of characters outside the set below:

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

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

NOT_MATCH_THISthe literal text NOT_MATCH_THIS (case sensitive)

Negated Character Class[^;\n]*

*matches any number of characters outside the set below:

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

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

Negated Character Class[^;\n]*

*matches any number of characters outside the set below:

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

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

PAT_Bthe literal text PAT_B (case sensitive)

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

Non-Capturing Group(?:[^;]*)

Negated Character Class[^;]*

*matches any number of characters outside the set below:

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

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

Regular Expression

^PAT_A_[^;\n]*(?:\n(?![^\n;]*NOT_MATCH_THIS)[^;\n]*)*\n[^;\n]*PAT_B.*(?:[^;]*);

New

PAT_A_YYY(
  OK,
  PAT_B
);

PAT_A_XXX(
  NOT_MATCH_THIS,
  PAT_B
);