Regular Expressions 101

(?s)applies the following effective flags to the remainder of the pattern: s

s modifier: single line. Allows a dot to match line terminators

<body>the literal text <body> (case sensitive)

\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match

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

<tagthe literal text <tag (case sensitive)

Non-Capturing Group(?:(?!<inner_block=25>).)+

+repeats the group contents below at least once:

Negative Lookahead(?!<inner_block=25>)

<inner_block=25>the literal text <inner_block=25> (case sensitive)

.any character

</tag>the literal text </tag> (case sensitive)

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?s)<body>\K\s*<tag(?:(?!<inner_block=25>).)+</tag>

New

<body>
<tag>
<number=1>
<inner_block=5>
</tag>
<tag>
<number=12>
<inner_block=15>
</tag>
<tag>
<number=21>
<inner_block=25>
</tag>
<tag>
<number=29>
<inner_block=35>
</tag>
</body>

Regular Expression

Substitution