Regular Expressions 101

^start of line

Group 1([^,]*,(\d\d)_[^,]*,[^,]*)

Negated Character Class[^,]*

*matches any number of characters outside the set below:

,the literal , (44₁₀ / 54₈ / 2C₁₆)

Group 2(\d\d)

\da digit

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Negated Character Class[^,]*

*matches any number of characters outside the set below:

,the literal , (44₁₀ / 54₈ / 2C₁₆)

Negated Character Class[^,]*

*matches any number of characters outside the set below:

,the literal , (44₁₀ / 54₈ / 2C₁₆)

Negative Lookbehind(?<!_\d\d)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

\da digit

,the literal , (44₁₀ / 54₈ / 2C₁₆)

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

s modifier: single line. Allows a dot to match line terminators

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

^([^,]*,(\d\d)_[^,]*,[^,]*)(?<!_\d\d),

New

test,12_blah,blubb,anything
test,34_blah,blu_34,doesn't matter
test,56_foo,bar,nevermind

$1_$2,

test,12_blah,blubb,anything
test,34_blah,blu_34,doesn't matter
test,56_foo,bar,nevermind