Regular Expressions 101

^start of line

Group 1(\d{4})

\d{4}a digit, repeated exactly 4 times

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group 2([^_]+)

Negated Character Class[^_]+

+matches at least one character outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group 3([^_]+)

Negated Character Class[^_]+

+matches at least one character outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group 4([^_ ]+)

Negated Character Class[^_ ]+

+matches at least one character outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

the literal (32₁₀ / 40₈ / 20₁₆)

Non-Capturing Group(?: $(\S+)(?: (\S+))?$)?

?repeats the group contents below at most once:

the literal (32₁₀ / 40₈ / 20₁₆)

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Group 5(\S+)

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

Non-Capturing Group(?: (\S+))?

?repeats the group contents below at most once:

the literal (32₁₀ / 40₈ / 20₁₆)

Group 6(\S+)

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

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

$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

^(\d{4})_([^_]+)_([^_]+)_([^_ ]+)(?: \((\S+)(?: (\S+))?\))?$

2022_UT_T1000_100 (Classification1 Classification2)
2022_UT_T1000_100 (Classification1)
2022_UT_T1000_100