regex101: PCRE (Legacy) Match Workspace

Pro

Positive Lookbehind(?<=H\d{3}\b)

Hthe literal H (72₁₀ / 110₈ / 48₁₆) (case sensitive)

\d{3}a digit, repeated exactly 3 times

\ban ASCII word boundary

Non-Capturing Group(?:(?!\+?H\d{3}\b|^End word\b)[\S\s])+

+repeats the group contents below at least once:

Negative Lookahead(?!\+?H\d{3}\b|^End word\b)

1st Alternative\+?H\d{3}\b

\+?optionally matches the literal + (43₁₀ / 53₈ / 2B₁₆)

Hthe literal H (72₁₀ / 110₈ / 48₁₆) (case sensitive)

\d{3}a digit, repeated exactly 3 times

\ban ASCII word boundary

2nd Alternative^End word\b

^start of line

End wordthe literal text End word (case sensitive)

\ban ASCII word boundary

Character Class[\S\s]

\Sany non-whitespace character

\sany whitespace character

Positive Lookahead(?=[\s\S]*\r?\nEnd word\b)

Character Class[\s\S]*

*matches any number of characters from the set below:

\sany whitespace character

\Sany non-whitespace character

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

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

End wordthe literal text End word (case sensitive)

\ban ASCII word boundary

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

25 tokens

Regular Expression

(?<=H\d{3}\b)(?:(?!\+?H\d{3}\b|^End word\b)[\S\s])+(?=[\s\S]*\r?\nEnd word\b)

New

Sample text
Sample text
Sample text
H319 asdkjczixuqweoiurqoiweqwrjasdkjfqwe qweiouqwroiu kjasdkj czkjxklqjwekjiouasdiiaosudou
oiuasodiucxzlkjqweoiu oqiwur H320 asdkqjwe askjdq xzc
H325 asjdhasjd zxcjh
H331+H341+H341 askdjvkjzx qweqrqwoe
End word
Sample text
Sample text

End word

Substitution

Sample text
Sample text
Sample text
H319 asdkjczixuqweoiurqoiweqwrjasdkjfqwe qweiouqwroiu kjasdkj czkjxklqjwekjiouasdiiaosudou
oiuasodiucxzlkjqweoiu oqiwur H320 asdkqjwe askjdq xzc
H325 asjdhasjd zxcjh
H331+H341+H341 askdjvkjzx qweqrqwoe
End word
Sample text
Sample text

End word