regex101: PCRE (Legacy) Substitution Workspace

1st Alternative^(.*;)?([0-9]+(#[0-9]+){2,}).*

^start of line

Group 1(.*;)?

?repeats the group contents below at most once:

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

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

Group 2([0-9]+(#[0-9]+){2,})

Character Class[0-9]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Group 3(#[0-9]+){2,}

{2,}repeats the group contents below at least 2 times:

#the literal # (35₁₀ / 43₈ / 23₁₆)

Character Class[0-9]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

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

2nd Alternative^([^;\n]+).*

^start of line

Group 4([^;\n]+)

Negated Character Class[^;\n]+

+matches at least one character outside the set below:

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

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

.*any 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

25 tokens

Regular Expression

^(.*;)?([0-9]+(#[0-9]+){2,}).*|^([^;\n]+).*

New

2#9#;2#37#65
 ->  2#37#65
2#9#;2#37#65;2#37#
  -> 2#37#65 
2#9#;2#37#65;2#37#;2#37#56
  -> 2#37#65 or 2#37#56
2#37#65;2#99
  -> 2#37#65
3#9#;3#37#65;3#37#36;2#37#56
  -> 3#37#65 or 3#37#36 or 2#37#56
2#37#;2#99#
  -> 2#37 or 2#99# ( in this case any value)

Substitution

$2$4

2#9#;2#37#65
 ->  2#37#65
2#9#;2#37#65;2#37#
  -> 2#37#65 
2#9#;2#37#65;2#37#;2#37#56
  -> 2#37#65 or 2#37#56
2#37#65;2#99
  -> 2#37#65
3#9#;3#37#65;3#37#36;2#37#56
  -> 3#37#65 or 3#37#36 or 2#37#56
2#37#;2#99#
  -> 2#37 or 2#99# ( in this case any value)