# Track numbers from malformed filenames
**URL:** https://community.mp3tag.de/t/track-numbers-from-malformed-filenames/13651
**Category:** Support
**Created:** [July 17, 2012, 2:35pm UTC](https://community.mp3tag.de/t/track-numbers-from-malformed-filenames/13651 "2012-07-17T14:35:49Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@w2irt](https://community.mp3tag.de/u/w2irt)
#### Post date: [July 17, 2012, 2:35pm UTC](https://community.mp3tag.de/t/track-numbers-from-malformed-filenames/13651/1 "2012-07-17T14:35:49Z")
Hi folks,
I'm trying to organize a fairly large library who's filename structure is constant but badly constructed. When the songs were ripped from source a leading dash (-) between the title and track number was omitted, but a space-dash-space ( - ) was added _after_ the track number. Thus:
**The Who - Won't Get Fooled Again 005 - .mp3**
instead of
**The Who - Won't Get Fooled Again - 005.mp3**
What I'm trying to accomplish is to extract the track number from the filename and move it into the TRACK # field, leaving the actual filename to read:
**The Who - Won't Get Fooled Again.mp3**
Thanks in advance!
---
### Author:  [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [July 17, 2012, 3:06pm UTC](https://community.mp3tag.de/t/track-numbers-from-malformed-filenames/13651/2 "2012-07-17T15:06:03Z")
> [@w2irt](#):
>
> ... When the songs were ripped from source a leading dash (-) between the title and track number was omitted, but a space-dash-space ( - ) was added _after_ the track number. Thus:
> **The Who - Won't Get Fooled Again 005 - .mp3**
> instead of
> **The Who - Won't Get Fooled Again - 005.mp3**
> What I'm trying to accomplish is to extract the track number from the filename and move it into the TRACK # field, leaving the actual filename to read:
> **The Who - Won't Get Fooled Again.mp3**
> Thanks in advance!
As always ... Mp3tag provides several ways to reach the goal ...
here is one way ... using the converter "Tag - Tag" ...
Step 1:
**Convert** | **Tag - Tag** | **ALT+5**
_Select format string_
Field: **TRACK**
Format string: **$regexp(%\_filename%,'^(.+?)\s0\*(\d+)\s.+?$','$2')**
Preview: **5**
Step 2:
**Convert** | **Tag - Tag** | **ALT+5**
_Select format string_
Field: **\_FILENAME**
Format string: **$regexp(%\_filename%,'^(.+?)\s0\*(\d+)\s.+?$','$1')**
Preview: **The Who - Won't Get Fooled Again**
... or ...
Step 1:
**Convert** | **Tag - Tag** | **ALT+5**
_Select format string_
Field: **TRACK**
Format string: **$num($cutLeft($trimRight(%\_filename%,' -'),$strrchr($trimRight(%\_filename%,' -'),' ')),1)**
... or ...
Format string: **$num($reverse($num($trimLeft($reverse(%\_filename%),' -'),1)),1)**
Preview: **5**
Step 2:
**Convert** | **Tag - Tag** | **ALT+5**
_Select format string_
Field: **\_FILENAME**
Format string: **$trimRight(%\_filename%,' -0123456789')**
Preview: **The Who - Won't Get Fooled Again**
... or using a group of actions ...
Begin Action Group **Test\_2012#20120717.w2irt.Guess**
Action #1
_Actiontype 7:_ **Import tag fields (guess values)**
_Source format \_\_:_ **$reverse(%\_filename%)**
_Guessing pattern:_ **%DUMMY% - %TRACK% %TITLE% - %ARTIST%**
Action #2
_Actiontype 5:_ **Format value**
_Field \_\_\_\_\_\_:_ **TRACK**
_Formatstring:_ **$num($reverse(%TRACK%),1)**
Action #3
_Actiontype 5:_ **Format value**
_Field \_\_\_\_\_\_:_ **TITLE**
_Formatstring:_ **$reverse(%TITLE%)**
Action #4
_Actiontype 5:_ **Format value**
_Field \_\_\_\_\_\_:_ **ARTIST**
_Formatstring:_ **$reverse(%ARTIST%)**
Action #5
_Actiontype 5:_ **Format value**
_Field \_\_\_\_\_\_:_ **\_FILENAME**
[i]Formatstring: **%ARTIST%' - '%TITLE%' - '$num(%TRACK%,3)**
End Action Group **Test\_2012#20120717.w2irt.Guess** (5 Actions)
DD.20120717.2007.CEST
---
### Author:  [@w2irt](https://community.mp3tag.de/u/w2irt)
#### Post date: [July 17, 2012, 3:35pm UTC](https://community.mp3tag.de/t/track-numbers-from-malformed-filenames/13651/3 "2012-07-17T15:35:29Z")
Wow. Worked perfectly! Thank you so much for saving me _ **hours** _ of tedious work--or, more likely, pushing this project off for another few years.
Thanks again!
> [@DetlevD](#):
>
> As always ... Mp3tag provides several ways to reach the goal ...
> here is one way ... using the converter "Tag - Tag" ...
>
> Step 1:
>
>
>
> **Convert** | **Tag - Tag** | **ALT+5**
>
>
>
> _Select format string_
>
>
>
> Field: **TRACK**
>
>
>
> Format string: **$regexp(%\_filename%,'^(.+?)\s0\*(\d+)\s.+?$','$2')**
>
>
>
> Preview: **5**
>
>
>
> Step 2:
>
>
>
> **Convert** | **Tag - Tag** | **ALT+5**
>
>
>
> _Select format string_
>
>
>
> Field: **\_FILENAME**
>
>
>
> Format string: **$regexp(%\_filename%,'^(.+?)\s0\*(\d+)\s.+?$','$1')**
>
>
>
> Preview: **The Who - Won't Get Fooled Again**
>
>
>
> DD.20120717.1905.CEST
---
### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:23pm UTC](https://community.mp3tag.de/t/track-numbers-from-malformed-filenames/13651/4 "2026-02-09T12:23:57Z")