# Filter files that have different filenames than expression

**URL:** <https://community.mp3tag.de/t/filter-files-that-have-different-filenames-than-expression/42942>\
**Category:** Support\
**Created:** [September 13, 2018, 5:22pm UTC](https://community.mp3tag.de/t/filter-files-that-have-different-filenames-than-expression/42942 "2018-09-13T17:22:58Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Gapa](https://community.mp3tag.de/user_avatar/community.mp3tag.de/gapa/32/5685_2.png) [@Gapa](https://community.mp3tag.de/u/Gapa)\
**Post date:** [September 13, 2018, 5:22pm UTC](https://community.mp3tag.de/t/filter-files-that-have-different-filenames-than-expression/42942/1 "2018-09-13T17:22:58Z")

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Is it possible to filter files to show only those that don't match a given string? I've tried this filter but it doesn't work:  
NOT "%\_filename%" IS "$num(%track%,2). %title%"

I want to find all files that have wrong filename without using 'Tag - Filename' function at the whole library, to avoid changing date modified.

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**Author:** ![ohrenkino](https://community.mp3tag.de/user_avatar/community.mp3tag.de/ohrenkino/32/4843_2.png) [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)\
**Post date:** [September 13, 2018, 5:58pm UTC](https://community.mp3tag.de/t/filter-files-that-have-different-filenames-than-expression/42942/2 "2018-09-13T17:58:16Z")

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You would have to use an expression in front of the operator:  
`"$if($eql(%_filename%,'$num(%track%,2). %title%'),1,0)" IS "1"`

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**Author:** ![Gapa](https://community.mp3tag.de/user_avatar/community.mp3tag.de/gapa/32/5685_2.png) [@Gapa](https://community.mp3tag.de/u/Gapa)\
**Post date:** [September 13, 2018, 7:19pm UTC](https://community.mp3tag.de/t/filter-files-that-have-different-filenames-than-expression/42942/3 "2018-09-13T19:19:38Z")

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Thank you very much, I forgot about that way.  
It works but with one change - removed single apostrophes:  
`"$if($eql(%_filename%,$num(%track%,2). %title%),1,0)" IS "0"`

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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, 12:27pm UTC](https://community.mp3tag.de/t/filter-files-that-have-different-filenames-than-expression/42942/4 "2026-02-09T12:27:40Z")

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