regex101: PCRE (Legacy) Match Workspace

Pro

^start of line

/?optionally matches the literal / (47₁₀ / 57₈ / 2F₁₆)

Negative Lookahead(?!system/)

system/the literal text system/ (case sensitive)

Non-Capturing Group(?:[-\w]+/)*

*repeats the group contents below any number of times:

Character Class[-\w]+

+matches at least one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\wany word character

/the literal / (47₁₀ / 57₈ / 2F₁₆)

Non-Capturing Group(?:index\.php|)

1st Alternativeindex\.php

indexthe literal text index (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

phpthe literal text php (case sensitive)

2nd Alternative — matches an empty string

Non-Capturing Group(?:\?[-&=\w]+|)

1st Alternative\?[-&=\w]+

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

Character Class[-&=\w]+

+matches at least one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

&the literal & (38₁₀ / 46₈ / 26₁₆)

=the literal = (61₁₀ / 75₈ / 3D₁₆)

\wany word character

2nd Alternative — matches an empty string

$end of line

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

^/?(?!system/)(?:[-\w]+/)*(?:index\.php|)(?:\?[-&=\w]+|)$

New

/abc/
//abc/
abc/
abc/abc/
/abc/index.php?utm_source=vk
/abc/abc/index.php?utm_source=vk
/systemsssss/abc/index.php?utm_source=vk
/system/sssss/abc/index.php?utm_source=vk
system/sssss/abc/index.php?utm_source=vk

Substitution

/abc/
//abc/
abc/
abc/abc/
/abc/index.php?utm_source=vk
/abc/abc/index.php?utm_source=vk
/systemsssss/abc/index.php?utm_source=vk
/system/sssss/abc/index.php?utm_source=vk
system/sssss/abc/index.php?utm_source=vk