05. Capture

Groups

Groupings are used when you want to match certain patterns, but only want to extract part of the information.

We can later reference these segments that we captured later on.

To specify a grouping, use parantheses (()).

([cat])\s\1
Matches any string in text where "c c", "a a" or "t t"

Nested groups

You can also nest capture parentheses. The captured groups are in the order in which they are defined.

Referencing

To reference the captured substrings, use a backslash (\).

\0
matches full text
\1
group 1
\2
group 2

Take your Linux skills to the next level!

Command Line Kung Fu

Take your Linux skills to the next level! Try Linux & UNIX

Command Line Kung Fu is packed with dozens of tips and practical real-world examples. You won't find theoretical examples in this book. The examples demonstrate how to solve actual problems. The tactics are easy to find, too. Each chapter covers a specific topic and groups related tips and examples together.

$ Check price
14.9914.99Amazon 4.5 logo(27+ reviews)

More Linux & UNIX resources

Ace your Technical Interview

Elements of Programming Interviews

Ace your Technical Interview Try Algorithms

Learn all the different scenarios of . This book is jam packed with code snippets written in C++ and Java to give you the edge you need to ace your technical interviews. Problems come with detailed solutions as well as a hint in case you get stuck, and organized by difficulty level with several variants to help you apply your knowledge more widely.

$ Check price
39.9539.95Amazon 4 logo(240+ reviews)

More Algorithms resources

Ad