Regular Expressions 101

^start of line

Positive Lookahead(?=.*[:|@](?=.+)(?!latest))

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

Character Class[:|@]

:the literal : (58₁₀ / 72₈ / 3A₁₆)

|the literal | (124₁₀ / 174₈ / 7C₁₆)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Positive Lookahead(?=.+)

.+any character (except for line terminators), repeated at least once

Negative Lookahead(?!latest)

latestthe literal text latest (case sensitive)

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

$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.

Search reference

Regular Expression

^(?=.*[:|@](?=.+)(?!latest)).*$

New

### Should PASS ###

fluentd:v2.5.2
k8s.gcr.io/ubuntu-slim:0.1
quay.io/fluentd_elasticsearch/fluentd:v2.5.2
ubuntu-slim:0.1

### Should FAIL ###

fluentd
k8s.gcr.io/ubuntu-slim
quay.io/fluentd_elasticsearch/fluentd:latest
ubuntu-slim:latest