Regular Expressions 101

Pro

^start of line

STARTING LINEthe literal text STARTING LINE (case sensitive)

Non-Capturing Group(?:.*(?:(?!\n(STARTING|ENDING) LINE)\n.*)*(?=\nSTARTING LINE)|(?![\s\S]*\nENDING LINE)[\s\S]*$)

1st Alternative.*(?:(?!\n(STARTING|ENDING) LINE)\n.*)*(?=\nSTARTING LINE)

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

Non-Capturing Group(?:(?!\n(STARTING|ENDING) LINE)\n.*)*

*repeats the group contents below any number of times:

Negative Lookahead(?!\n(STARTING|ENDING) LINE)

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

Group 1(STARTING|ENDING)

1st AlternativeSTARTING

STARTINGthe literal text STARTING (case sensitive)

2nd AlternativeENDING

ENDINGthe literal text ENDING (case sensitive)

LINEthe literal text LINE (case sensitive)

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

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

Positive Lookahead(?=\nSTARTING LINE)

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

STARTING LINEthe literal text STARTING LINE (case sensitive)

2nd Alternative(?![\s\S]*\nENDING LINE)[\s\S]*$

Negative Lookahead(?![\s\S]*\nENDING LINE)

Character Class[\s\S]*

*matches any number of characters from the set below:

\sa Unicode whitespace character

\Sany character that is not Unicode whitespace

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

ENDING LINEthe literal text ENDING LINE (case sensitive)

Character Class[\s\S]*

*matches any number of characters from the set below:

\sa Unicode whitespace character

\Sany character that is not Unicode whitespace

$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

Detailed match information will be displayed here automatically.

25 tokens

^STARTING LINE(?:.*(?:(?!\n(STARTING|ENDING) LINE)\n.*)*(?=\nSTARTING LINE)|(?![\s\S]*\nENDING LINE)[\s\S]*$)

New

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STARTING LINE with something 83
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STARTING LINE with other 12
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ENDING LINE with yet another info
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STARTING LINE with another 43
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STARTING LINE with something 83
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STARTING LINE with other 12
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ENDING LINE with yet another info
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STARTING LINE with another 43
...