# Understanding Regular Expressions

**URL:** https://community.mp3tag.de/t/understanding-regular-expressions/4356
**Category:** Support
**Created:** [January 19, 2007, 3:17pm UTC](https://community.mp3tag.de/t/understanding-regular-expressions/4356 "2007-01-19T15:17:55Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![DetlevD](https://community.mp3tag.de/user_avatar/community.mp3tag.de/detlevd/32/123_2.png) [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [January 19, 2007, 3:17pm UTC](https://community.mp3tag.de/t/understanding-regular-expressions/4356/1 "2007-01-19T15:17:55Z")

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Giving a directory name: ' **CD 2 Latin For Lovers**'  
using a regular expression: **$regexp(%\_directory%, \*(CD) \*\d+,$1,0)**  
I would expect to get the result: ' **CD**'  
but actually the result is: ' **CD Latin For Lovers**'

What is wrong?

DD.20070119.1712

This returns the string "CD" ...

**$regexp('CD 2 Latin For Lovers','^.\*(CD) \d+ .\*$','$1',0)**

DD.201200712.1429.CEST

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### Author: ![system](https://community.mp3tag.de/uploads/default/original/2X/c/ce7035d426cb755a7916793326d23b465222a407.png) [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:20pm UTC](https://community.mp3tag.de/t/understanding-regular-expressions/4356/2 "2026-02-09T12:20:06Z")

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