Regular Expressions 101

^start of line

Group 1(.{20})

.{20}any character (except for line terminators), repeated exactly 20 times

Negated Character Class[^.]{4,}

{4,}matches at least 4 characters outside the set below:

.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 2(.*)

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

$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

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(.{20})[^.]{4,}(.*)$

Test String
New

1.1234567890.ab
2.123456789012345678901.ab
3.1234567890123456789012.ab
4.12345678901234567890123.ab
5.123456789012345678901234.ab
6.1234567890123456789012345.ab
7.12345678901234567890123456.ab
8.123456789012345678901234567890.ab
9.123456789012345678901234567890.1234567890123456.7890.ab
0.123456789012345678901234567890.12345678901.234567890....abcdef012345
  12345678901234567890123456789012345678901234567890

Regular Expression

Test StringNew

Test String
New