Regular Expressions 101

^start of line

Non-Capturing Group(?:[^:\n]+://)?

?repeats the group contents below at most once:

Negated Character Class[^:\n]+

+matches at least one character outside the set below:

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\na line-feed (newline) character (ASCII 10)

://the literal text ://

Group 1([^:#/\n]*)

Negated Character Class[^:#/\n]*

*matches any number of characters outside the set below:

:the literal : (58₁₀ / 72₈ / 3A₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

/the literal / (47₁₀ / 57₈ / 2F₁₆)

\na line-feed (newline) character (ASCII 10)

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.

Search reference

Regular Expression

^(?:[^:\n]+://)?([^:#/\n]*)

New

http://www.google.com/
https://www.google.com:2000/
http://100.1.25.3:8000/foo/bar?abc.php=xxxx+xxxx
www.google.com
10.0.2.2:5000
localhost/
localhost/foo
google.com
http://///x

Regular Expression

Substitution