Regular Expressions 101

Pro

^start of line

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Group 1((?:(?:(?!{.*?})[^-\n]|{.*?})|(?:(?:(?!{.*?})[^-\n]|{.*?})*?-){2})*)

Non-Capturing Group(?:(?:(?!{.*?})[^-\n]|{.*?})|(?:(?:(?!{.*?})[^-\n]|{.*?})*?-){2})*

*repeats the group contents below any number of times:

1st Alternative(?:(?!{.*?})[^-\n]|{.*?})

Non-Capturing Group(?:(?!{.*?})[^-\n]|{.*?})

1st Alternative(?!{.*?})[^-\n]

Negative Lookahead(?!{.*?})

{the literal { (123₁₀ / 173₈ / 7B₁₆)

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

}the literal } (125₁₀ / 175₈ / 7D₁₆)

Negated Character Class[^-\n]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

2nd Alternative{.*?}

{the literal { (123₁₀ / 173₈ / 7B₁₆)

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

}the literal } (125₁₀ / 175₈ / 7D₁₆)

2nd Alternative(?:(?:(?!{.*?})[^-\n]|{.*?})*?-){2}

Non-Capturing Group(?:(?:(?!{.*?})[^-\n]|{.*?})*?-){2}

{2}repeats the group contents below exactly 2 times:

Non-Capturing Group(?:(?!{.*?})[^-\n]|{.*?})*?

*?repeats the group contents below any number of times:

1st Alternative(?!{.*?})[^-\n]

Negative Lookahead(?!{.*?})

{the literal { (123₁₀ / 173₈ / 7B₁₆)

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

}the literal } (125₁₀ / 175₈ / 7D₁₆)

Negated Character Class[^-\n]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

2nd Alternative{.*?}

{the literal { (123₁₀ / 173₈ / 7B₁₆)

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

}the literal } (125₁₀ / 175₈ / 7D₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

Ready to run

25 tokens

^-((?:(?:(?!{.*?})[^-\n]|{.*?})|(?:(?:(?!{.*?})[^-\n]|{.*?})*?-){2})*)-