regex101: ChromeOS user agent

Explanation

Pro

Group 1(((\w\d+|\w+)(\W+)?)?(\s+)?(U;)?(\s+)?(CrOS|Cross|CrossOS))

Group 2((\w\d+|\w+)(\W+)?)?

?repeats the group contents below at most once:

Group 3(\w\d+|\w+)

1st Alternative\w\d+

\wany word character

\d+a digit, repeated at least once

2nd Alternative\w+

\w+any word character, repeated at least once

Group 4(\W+)?

?repeats the group contents below at most once:

\W+any non-word character, repeated at least once

Group 5(\s+)?

?repeats the group contents below at most once:

\s+any whitespace character, repeated at least once

Group 6(U;)?

?repeats the group contents below at most once:

U;the literal text U; (case insensitive)

Group 7(\s+)?

?repeats the group contents below at most once:

\s+any whitespace character, repeated at least once

Group 8(CrOS|Cross|CrossOS)

1st AlternativeCrOS

CrOSthe literal text CrOS (case insensitive)

2nd AlternativeCross

Crossthe literal text Cross (case insensitive)

3rd AlternativeCrossOS

CrossOSthe literal text CrossOS (case insensitive)

Group 9(\s+)

\s+any whitespace character, repeated at least once

Group 10(x86_64|x8664|x86_x64|armv\d+|aarch\d+|i\d+|amd64)

1st Alternativex86_64

x86_64the literal text x86_64 (case insensitive)

2nd Alternativex8664

x8664the literal text x8664 (case insensitive)

3rd Alternativex86_x64

x86_x64the literal text x86_x64 (case insensitive)

4th Alternativearmv\d+

armvthe literal text armv (case insensitive)

\d+a digit, repeated at least once

5th Alternativeaarch\d+

aarchthe literal text aarch (case insensitive)

\d+a digit, repeated at least once

6th Alternativei\d+

ithe literal i (105₁₀ / 151₈ / 69₁₆) (case insensitive)

\d+a digit, repeated at least once

7th Alternativeamd64

amd64the literal text amd64 (case insensitive)

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

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

Quick Reference

25 tokens

Regular Expression

(((\w\d+|\w+)(\W+)?)?(\s+)?(U;)?(\s+)?(CrOS|Cross|CrossOS))(\s+)(x86_64|x8664|x86_x64|armv\d+|aarch\d+|i\d+|amd64)

New

     331  Mozilla/5.0 (X11; U; CrOS i686 0.9.128; ru) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.343 Safari/534.10
     638  Mozilla/5.0 (X11; U; CrOS i686 0.9.128; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.343 Safari/534.10
     661  Mozilla/5.0 (X11; U; CrOS i686 0.9.128; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.341 Safari/534.10
     667  Mozilla/5.0 (X11; U; CrOS i686 0.13.507) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36
     744  Mozilla/5.0 (X11; U; CrOS i686 0.13.507) AppleWebKit/600.7.12 (KHTML, like Gecko) Version/8.0.7 Safari/600.7.12
     903  Mozilla/5.0 (X11; U; CrOS i686 9.10.0; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.0.253.0 Safari/532.5
     949  Mozilla/5.0 (x11; Cross x86_64 12739.105.0) Applewebkit/537.36 (KHTML, like gecko)Chrome/80.0.3987.158 Safari/537.36
    1147  Mozilla/5.0 (Wizyconf CrOS x86_64 11021.111.2020 9c7514400ffe) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/

Substitution

     331  Mozilla/5.0 (X11; U; CrOS i686 0.9.128; ru) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.343 Safari/534.10
     638  Mozilla/5.0 (X11; U; CrOS i686 0.9.128; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.343 Safari/534.10
     661  Mozilla/5.0 (X11; U; CrOS i686 0.9.128; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.341 Safari/534.10
     667  Mozilla/5.0 (X11; U; CrOS i686 0.13.507) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36
     744  Mozilla/5.0 (X11; U; CrOS i686 0.13.507) AppleWebKit/600.7.12 (KHTML, like Gecko) Version/8.0.7 Safari/600.7.12
     903  Mozilla/5.0 (X11; U; CrOS i686 9.10.0; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.0.253.0 Safari/532.5
     949  Mozilla/5.0 (x11; Cross x86_64 12739.105.0) Applewebkit/537.36 (KHTML, like gecko)Chrome/80.0.3987.158 Safari/537.36
    1147  Mozilla/5.0 (Wizyconf CrOS x86_64 11021.111.2020 9c7514400ffe) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/