Regular Expressions 101

Explanation

Pro

^start of line

\d{1,4}a Unicode decimal digit, repeated between 1 and 4 times

Character Class[_]

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

.*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.

25 tokens

^\d{1,4}[_].*

1234_test.mp3
999_test.mp3
12_test.mp3
0_test.mp3
0t_est.mp34
t_est1234.mp3
@_test.mp3
/_test.mp3
\\_test.mp3

1234_test.mp3
999_test.mp3
12_test.mp3
0_test.mp3
0t_est.mp34
t_est1234.mp3
@_test.mp3
/_test.mp3
\\_test.mp3