# who can help with a special regular expression?
**URL:** https://community.mp3tag.de/t/who-can-help-with-a-special-regular-expression/10827
**Category:** Support
**Created:** [September 18, 2010, 6:51pm UTC](https://community.mp3tag.de/t/who-can-help-with-a-special-regular-expression/10827 "2010-09-18T18:51:40Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@globetrotters1](https://community.mp3tag.de/u/globetrotters1)
#### Post date: [September 18, 2010, 6:51pm UTC](https://community.mp3tag.de/t/who-can-help-with-a-special-regular-expression/10827/1 "2010-09-18T18:51:40Z")
Hi,
I often have the problem that in a track file name like
**Flute Sonata B-Dur**
an "in" is missing, so it will read
**Flute Sonata in B-Dur**
Only problem is that it can be A-Dur through H-Dur and a-moll through h-moll and it should exclude the strings which already have an "in " in front of the Dur/moll - furthermore there are the As, Des, Fis, Cis etc values in front of the -Dur and -moll possible
Who can help?
thanks
---
### Author:  [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [September 19, 2010, 5:02am UTC](https://community.mp3tag.de/t/who-can-help-with-a-special-regular-expression/10827/2 "2010-09-19T05:02:18Z")
> [@globetrotters1](#):
>
> ... I often have the problem that in a track file name like
> **Flute Sonata B-Dur**
> an "in" is missing, so it will read
> **Flute Sonata in B-Dur**...
1.
You may deepen your knowledge on the key signatures.
[http://en.wikipedia.org/wiki/Circle\_of\_fifths](http://en.wikipedia.org/wiki/Circle_of_fifths)
[http://de.wikipedia.org/wiki/Quintenzirkel](http://de.wikipedia.org/wiki/Quintenzirkel)
1.
I understand your request this way.
You want to manipulate a given filename:
"Flute Sonata B-Dur"
You want to insert the word "in" before a word which is a key signature to get the filename:
"Flute Sonata in B-Dur"
You want not to change filenames which are already have the word "in" before a key signature.
1.
Use Mp3tag list view. Press [F3] to open the Filter dialog.
There might exist several expressions to filter your file base in order to see only those files, which do not have the word "in" before a key signature.
First see what files have already the word "in" before a key signature:
**%\_FILENAME% MATCHES "^(.+) in ((?:.+?)-(?:moll|Dur))(.\*)$"**
To see all files which do not have the word "in" before a key signature:
**NOT %\_FILENAME% MATCHES "^(.+) in ((?:.+?)-(?:moll|Dur))(.\*)$"**
There might be other files shown which are not of interest, so you have to do some refinement on the filter expression.
Examples:
**(("%\_FILENAME%" HAS "-moll") OR ("%\_FILENAME%" HAS "-Dur")) AND NOT ("%\_FILENAME%" HAS " in ")**
**NOT %\_FILENAME% MATCHES "^(.+) in ((?:.+?)-(?:moll|Dur))(.\*)$" AND (("%\_FILENAME%" HAS "-moll") OR ("%\_FILENAME%" HAS "-Dur"))**
1.
Set the filter to see only files, which do not have the word "in" before a key signature.
Use an action **"Replace with Regular Expression"**
Field: **%\_FILENAME%**
Regular expression: **^(.+)\s((?:.+?)-(?:moll|Dur))(.\*)$**
Replace matches with: **$1 in $2$3**
Case-sensitive comparison: **yes**
Alternative:
Action **"Format value"**
Field: **%\_FILENAME%**
Formatstring: **$regexp(%\_FILENAME%,'(?-i)^(.+)\s((?:.+?)-(?:moll|Dur))(.\*)$','$1 in $2$3')**
1.
Ready.
DD.20100919.0900.CEST
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### Author:  [@globetrotters1](https://community.mp3tag.de/u/globetrotters1)
#### Post date: [September 25, 2010, 11:59am UTC](https://community.mp3tag.de/t/who-can-help-with-a-special-regular-expression/10827/3 "2010-09-25T11:59:36Z")
DetlevD,
many thanks for your kind help!
Very much appreciated
And you are right, I didn't know certain details of the key signatures
Your hint is very valuable for me...
Every day learning something new!
🙂
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### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:22pm UTC](https://community.mp3tag.de/t/who-can-help-with-a-special-regular-expression/10827/4 "2026-02-09T12:22:33Z")