Regular Expressions 101

Pro

^start of line

Group 1(.*)

.*any character (except for line terminators), repeated any number of times

Group 2(\/(?!no-trailing-slash)([^.\/])+)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Negative Lookahead(?!no-trailing-slash)

no-trailing-slashthe literal text no-trailing-slash (case sensitive)

Group 3([^.\/])+

+repeats the group contents below at least once:

Negated Character Class[^.\/]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

$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

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

^(.*)(\/(?!no-trailing-slash)([^.\/])+)$

New

www.site.com/foo
www.site.com/foo/
www.site.com/foo/baz.xml
www.site.com/no-trailing-slash
www.site.com/no-trailing-slash2
www.site.com/no-trailing-slasf

Substitution

$1$2/

www.site.com/foo
www.site.com/foo/
www.site.com/foo/baz.xml
www.site.com/no-trailing-slash
www.site.com/no-trailing-slash2
www.site.com/no-trailing-slasf