Regular Expressions 101

(?sm)applies the following effective flags to the remainder of the pattern: gusm

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

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

^start of line

Group 1([^,]+?)

Negated Character Class[^,]+?

+?matches at least one character outside the set below:

,the literal , (44₁₀ / 54₈ / 2C₁₆)

.+?any Unicode character, repeated at least once

Non-Capturing Group(?:(\n(?!\1))|\Z)

1st Alternative(\n(?!\1))

Group 2(\n(?!\1))

\na line-feed (newline) character (ASCII 10)

Negative Lookahead(?!\1)

\1the text saved by group 1

2nd Alternative\Z

\Zend of string, or before its final line terminator

Global pattern flags

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

u modifier: unicode. Treats the pattern and subject as UTF-16

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?sm)^([^,]+?),.+?(?:(\n(?!\1))|\Z)

New

Christi,19946752,20194048
Christi,20369664,20520192
Christi,20520192,20631296
Christi,20123984,20124432
Brandon,20194048,20369664
Brandon,20745984,20980736
Brandon,22341211,22443280
Joe-010,28729383,28733432
Joe-010,23488449,23499482