Regular Expressions 101

^start of string

Non-Capturing Group(?:[^\s]+\s++){4}

{4}repeats the group contents below exactly 4 times:

Negated Character Class[^\s]+

+matches at least one character outside the set below:

\sany whitespace character

\s++any whitespace character, repeated at least once

Group logical_system(?<logical_system>[\w]+)

Character Class[\w]+

+matches at least one character from the set below:

\wany word character

Character Class[:\s]

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\sany whitespace character

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?:[^\s]+\s++){4}(?<logical_system>[\w]+)[:\s]

Test String
New

Nov 15 02:51:46 CRTR2OTN.HKB VIASAT2OTN rpd[15644]: bgp_select_myaddr: peer 172.16.145.132 (External AS 64947) local address 172.16.145.129 unavailable, connection failed
Nov 15 02:51:44 CRTR2OTN.SIN rmopd[2167] pingCtlOwnerIndex = Rpm-Bgp-Owner, pingCtlTestName = Rpm-Bgp-Test-7

Regular Expression

Test StringNew

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Test String
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