Regular Expressions 101

^start of line

Group 1((?:::|[^:])*+)

Non-Capturing Group(?:::|[^:])*+

*+repeats the group contents below any number of times:

1st Alternative::

::the literal text ::

2nd Alternative[^:]

Negated Character Class[^:]

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Negative Lookahead(?!.*(?<!:):(?!:))

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

Negative Lookbehind(?<!:)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Negative Lookahead(?!:)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

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

^((?:::|[^:])*+):(?!.*(?<!:):(?!:))

New

JohnP: random text here
BobF::student: random text here (this is valid because there's only ONE occurrence of a single colon. the other is a double colon)
Paris: random text here::student (valid for the same reason as above)
JohnP: student: random text here
BobF::student: random text here: more
Bill:: xyz

Regular Expression

Extraction