Regular Expressions 101

Explanation

Pro

Group check_all(?<check_all> [ ]+ \[(?<check_content>X|[[:blank:]\h])\] [ ]+ (?=\S+) )

Character Class[ ]+

+matches at least one character from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

Group check_content(?<check_content>X|[[:blank:]\h])

1st AlternativeX

Xthe literal X (88₁₀ / 130₈ / 58₁₆) (case insensitive)

2nd Alternative[[:blank:]\h]

Character Class[[:blank:]\h]

[:blank:]a whitespace character, excluding line breaks [ \t]

\hany horizontal whitespace character

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

Character Class[ ]+

+matches at least one character from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

Positive Lookahead(?=\S+)

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

Global pattern flags

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

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

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

Ready to run

25 tokens

(?<check_all>
    [ ]+
    \[(?<check_content>X|[[:blank:]\h])\]
    [ ]+
    (?=\S+)
)