Regular Expressions 101

\d+a Unicode decimal digit, repeated at least once

day-the literal text day- (case sensitive)

Group 1(\d{4}-\d{1,2}-\d{1,2})

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{1,2}a Unicode decimal digit, repeated between 1 and 2 times

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{1,2}a Unicode decimal digit, repeated between 1 and 2 times

--the literal text --

.*any Unicode character (except for line terminators), repeated any number of times

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+day-(\d{4}-\d{1,2}-\d{1,2})--.*

New

2day-2023-1-5--20-0.csv
1day-2023-2-5--20-0.csv
3day-2021-1-5--20-0.csv
103day-2021-1-5--20-0.csv

\1