regex101: PCRE (Legacy) Substitution Workspace

^start of line

Group 1(https?:\/{2}[^\/]+\/search\?)

httpthe literal text http (case sensitive)

s?optionally matches the literal s (115₁₀ / 163₈ / 73₁₆) (case sensitive)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\/{2}the literal / (47₁₀ / 57₈ / 2F₁₆) , repeated exactly 2 times

Negated Character Class[^\/]+

+matches at least one character outside the set below:

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

searchthe literal text search (case sensitive)

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

Group 2(q=[^\s&]+(?:\&(?!ei=|gws_rd=)[^\s&]*)*)

q=the literal text q= (case sensitive)

Negated Character Class[^\s&]+

+matches at least one character outside the set below:

\sany whitespace character

&the literal & (38₁₀ / 46₈ / 26₁₆)

Non-Capturing Group(?:\&(?!ei=|gws_rd=)[^\s&]*)*

*repeats the group contents below any number of times:

\&the literal & (38₁₀ / 46₈ / 26₁₆)

Negative Lookahead(?!ei=|gws_rd=)

1st Alternativeei=

ei=the literal text ei= (case sensitive)

2nd Alternativegws_rd=

gws_rd=the literal text gws_rd= (case sensitive)

Negated Character Class[^\s&]*

*matches any number of characters outside the set below:

\sany whitespace character

&the literal & (38₁₀ / 46₈ / 26₁₆)

Group 3(\&gws_rd=[^\s&]*)?

?repeats the group contents below at most once:

\&the literal & (38₁₀ / 46₈ / 26₁₆)

gws_rd=the literal text gws_rd= (case sensitive)

Negated Character Class[^\s&]*

*matches any number of characters outside the set below:

\sany whitespace character

&the literal & (38₁₀ / 46₈ / 26₁₆)

Group 4(\&ei=[^\s&]*)

\&the literal & (38₁₀ / 46₈ / 26₁₆)

ei=the literal text ei= (case sensitive)

Negated Character Class[^\s&]*

*matches any number of characters outside the set below:

\sany whitespace character

&the literal & (38₁₀ / 46₈ / 26₁₆)

$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

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

Search reference

Regular Expression

^(https?:\/{2}[^\/]+\/search\?)(q=[^\s&]+(?:\&(?!ei=|gws_rd=)[^\s&]*)*)(\&gws_rd=[^\s&]*)?(\&ei=[^\s&]*)$

Unit Tests

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