Regular Expressions 101

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

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Non-Capturing Group(?:^require_once|(?<!^)\G)

1st Alternative^require_once

^start of line

require_oncethe literal text require_once (case sensitive)

2nd Alternative(?<!^)\G

Negative Lookbehind(?<!^)

^start of line

\Gstart of current search

Negated Character Class[^\\]*?

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

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

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

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?m)(?:^require_once|(?<!^)\G)[^\\]*?\K\\

New

no_require ab\ \ \
require_once $doc_root . "\inc\common.php";
require_once $doc_root . "\inc\admin_login.php";
require_once $doc_root . "\inc\usps_functions.php";
require_once $doc_root . '\lib\PDFMerger\PDFMerger.php';