regex101: PCRE (Legacy) Match Workspace

1st Alternative(?:^\d+:[^:\r\n]+:$|^:[^:\r\n]+:\d+$|^(?!.*:\b\S+\b:).*$)(*SKIP)(*FAIL)

Non-Capturing Group(?:^\d+:[^:\r\n]+:$|^:[^:\r\n]+:\d+$|^(?!.*:\b\S+\b:).*$)

1st Alternative^\d+:[^:\r\n]+:$

^start of line

\d+a digit, repeated at least once

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Negated Character Class[^:\r\n]+

+matches at least one character outside the set below:

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\ra carriage return (ASCII 13)

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

:the literal : (58₁₀ / 72₈ / 3A₁₆)

$end of line

2nd Alternative^:[^:\r\n]+:\d+$

^start of line

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Negated Character Class[^:\r\n]+

+matches at least one character outside the set below:

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\ra carriage return (ASCII 13)

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

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\d+a digit, repeated at least once

$end of line

3rd Alternative^(?!.*:\b\S+\b:).*$

^start of line

Negative Lookahead(?!.*:\b\S+\b:)

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

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\ban ASCII word boundary

\S+any non-whitespace character, repeated at least once

\ban ASCII word boundary

:the literal : (58₁₀ / 72₈ / 3A₁₆)

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

$end of line

(*SKIP)acts like (*PRUNE), but the next unanchored match attempt starts where (*SKIP) was reached instead of at the next subject character

(*FAIL)forces the current match attempt to fail at this position

2nd Alternative:[a-z0-9]+:

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Character Class[a-z0-9]+

+matches at least one character from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

: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

Search reference

Regular Expression

(?:^\d+:[^:\r\n]+:$|^:[^:\r\n]+:\d+$|^(?!.*:\b\S+\b:).*$)(*SKIP)(*FAIL)|:[a-z0-9]+:

New

:match1::match2: :match3:
:match4:
000:matchNot:
:matchNot:000
:match Not: