regex101: PCRE (Legacy) Match Workspace

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

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

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

<divthe literal text <div (case insensitive)

Positive Lookahead(?=(?:[^>"']|"[^"]*"|'[^']*')*?\sid\s*=\s*(?:(['"])\s*(post-\d+).*?\1))

Non-Capturing Group(?:[^>"']|"[^"]*"|'[^']*')*?

*?repeats the group contents below any number of times:

1st Alternative[^>"']

Negated Character Class[^>"']

>the literal > (62₁₀ / 76₈ / 3E₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

'the literal ' (39₁₀ / 47₈ / 27₁₆)

2nd Alternative"[^"]*"

"the literal " (34₁₀ / 42₈ / 22₁₆)

Negated Character Class[^"]*

*matches any number of characters outside the set below:

"the literal " (34₁₀ / 42₈ / 22₁₆)

3rd Alternative'[^']*'

'the literal ' (39₁₀ / 47₈ / 27₁₆)

Negated Character Class[^']*

*matches any number of characters outside the set below:

'the literal ' (39₁₀ / 47₈ / 27₁₆)

\sany whitespace character

idthe literal text id (case insensitive)

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

=the literal = (61₁₀ / 75₈ / 3D₁₆)

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

Non-Capturing Group(?:(['"])\s*(post-\d+).*?\1)

Group 1(['"])

Character Class['"]

'the literal ' (39₁₀ / 47₈ / 27₁₆)

"the literal " (34₁₀ / 42₈ / 22₁₆)

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

Group 2(post-\d+)

post-the literal text post- (case insensitive)

\d+a digit, repeated at least once

.*?any character, repeated any number of times

\1the text saved by group 1

\s+any whitespace character, repeated at least once

Non-Capturing Group(?:".*?"|'.*?'|[^>]*?)+

+repeats the group contents below at least once:

1st Alternative".*?"

"the literal " (34₁₀ / 42₈ / 22₁₆)

.*?any character, repeated any number of times

"the literal " (34₁₀ / 42₈ / 22₁₆)

2nd Alternative'.*?'

'the literal ' (39₁₀ / 47₈ / 27₁₆)

.*?any character, repeated any number of times

'the literal ' (39₁₀ / 47₈ / 27₁₆)

3rd Alternative[^>]*?

Negated Character Class[^>]*?

*?matches any number of characters outside the set below:

>the literal > (62₁₀ / 76₈ / 3E₁₆)

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

Search reference

Regular Expression

(?si)<div(?=(?:[^>"']|"[^"]*"|'[^']*')*?\sid\s*=\s*(?:(['"])\s*(post-\d+).*?\1))\s+(?:".*?"|'.*?'|[^>]*?)+>

New

<div class="main>
<div id="post-1111:">
<div class=junk id="post-1112:">
<div id="post-1113:" class=junk >
<div class=junk id="data-1122:" id="post-1114:">

Regular Expressions 101

Regular Expression

Substitution