# How to filter filenames that start with only lowercase? **URL:** \ **Category:** Support\ **Created:** [April 22, 2012, 11:53pm UTC](https://community.mp3tag.de/t/how-to-filter-filenames-that-start-with-only-lowercase/13349 "2012-04-22T23:53:19Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Mandah](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/m/8e8cbc/32.png) [@Mandah](https://community.mp3tag.de/u/Mandah)\ **Post date:** [April 22, 2012, 11:53pm UTC](https://community.mp3tag.de/t/how-to-filter-filenames-that-start-with-only-lowercase/13349/1 "2012-04-22T23:53:19Z")
I tried **%\_filename% MATCHES ^\l** but that seems to return any filename that starts with a word character; it is not bringing me only filenames that start with lowercase letters. Grrr, what to do? ---
**Author:** ![stevehero](https://community.mp3tag.de/user_avatar/community.mp3tag.de/stevehero/32/337_2.png) [@stevehero](https://community.mp3tag.de/u/stevehero)\ **Post date:** [April 23, 2012, 1:05am UTC](https://community.mp3tag.de/t/how-to-filter-filenames-that-start-with-only-lowercase/13349/2 "2012-04-23T01:05:24Z")
Use: **%\_filename% MATCHES (?-i)^\l** You have to force the search function within mp3tag to search case sensitive. Not sure if its a bug or not but the (?-i) matches the remainder of the regexp as case sensitive. If and I assume you want to change the 1st letter of the string to UPPER case then here is the action to match: _Action type:_ **Replace with regular expression** _Field:_ **\_FILENAME** _Regular expression:_ **^([a-z])** _Replace matches with:_ **$upper($1)** [x] case-sensitive comparison Make sure case sensitive comparison is checked. ---
**Author:** ![Mandah](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/m/8e8cbc/32.png) [@Mandah](https://community.mp3tag.de/u/Mandah)\ **Post date:** [April 23, 2012, 9:44am UTC](https://community.mp3tag.de/t/how-to-filter-filenames-that-start-with-only-lowercase/13349/3 "2012-04-23T09:44:58Z")
> [@stevehero](#): > > Use: > **%\_filename% MATCHES (?-i)^\l** > > You have to force the search function within mp3tag to search case sensitive. Not sure if its a bug or not but the (?-i) matches the remainder of the regexp as case sensitive. Thanks =) its actually because I was trying to delete spaces, hypens, periods and numbers that were before any of those characters but I ended up deleting that plus the first character of every single filename! I've just been semi-manually changing them all back (mp3tag crashed when I tried to undo changes). Sigh. I haven't had the time to learn codes so thanks very much for the reply. ---
**Author:** ![stevehero](https://community.mp3tag.de/user_avatar/community.mp3tag.de/stevehero/32/337_2.png) [@stevehero](https://community.mp3tag.de/u/stevehero)\ **Post date:** [April 23, 2012, 11:29am UTC](https://community.mp3tag.de/t/how-to-filter-filenames-that-start-with-only-lowercase/13349/4 "2012-04-23T11:29:49Z")
> [@Mandah.](#): > > Thanks =) its actually because I was trying to delete spaces, hypens, periods and numbers that were before any of those characters but I ended up deleting that plus the first character of every single filename! I've just been semi-manually changing them all back (mp3tag crashed when I tried to undo changes). Sigh. I haven't had the time to learn codes so thanks very much for the reply. Opps! 😳 But as the saying goes you always learn the hard way. So a good rule of thumb is to test on dummy/single files first. ---
**Author:** ![incifinci](https://community.mp3tag.de/user_avatar/community.mp3tag.de/incifinci/32/6526_2.png) [@incifinci](https://community.mp3tag.de/u/incifinci)\ **Post date:** [November 5, 2021, 8:44pm UTC](https://community.mp3tag.de/t/how-to-filter-filenames-that-start-with-only-lowercase/13349/5 "2021-11-05T20:44:25Z")
> [@stevehero](#): > > **%\_filename% MATCHES (?-i)^\l** > > You have to force the search function within mp3tag to search case sensitive. Dear @Florian, i think, this should be included [in the help](https://docs.mp3tag.de/actions/replace-regexp). * * * By the way, \[1\] is not a solution for non latin characters. But **\l** find them. And: you must to **repeat in every filter part**. This one does not work: `probleme IS "Lowercase name" OR %composer% MATCHES (?-i)^\l OR %arranger% MATCHES ^\l OR %lyricist% MATCHES ^\l OR %albumartist% MATCHES ^\l OR %artist% MATCHES ^\l OR %conductor% MATCHES ^\l` This one does: `probleme IS "Lowercase name" OR %composer% MATCHES (?-i)^\l OR %arranger% MATCHES (?-i)^\l OR %lyricist% MATCHES (?-i)^\l OR %albumartist% MATCHES (?-i)^\l OR %artist% MATCHES (?-i)^\l OR %conductor% MATCHES (?-i)^\l` * * * Unfortunately, this second variant is not perfect, too: it does not find lowercase in the second, third composer/artist etc. It seems, line start (^) means the whole list's start, in this case. I could not find a solution. I tried even this: `"$ifgreater($strstr($regexp($meta_sep(composer,â—†),'â—†(?-i)\l',â—†,0),â—†),0,1,)" IS 1` ...with no success. (It finds **all** files with multiple composer, even with uppercase start.) To repeat the filter for all, from $meta(composer,0) to $meta(composer,10) is not very comfortable. All right, i do now a temporarly filter expression, repeating all for some possible items (composer 1st, 2nd, 3rd...), but it would be better, **if somebody could tell a nice, real solution**. So, anyone, who needs it, can copy this temporary filter: > probleme IS "Lowercase name" OR "$meta(composer,0)" MATCHES (?-i)^\l OR "$meta(composer,1)" MATCHES (?-i)^\l OR "$meta(composer,2)" MATCHES (?-i)^\l OR "$meta(composer,3)" MATCHES (?-i)^\l OR "$meta(composer,4)" MATCHES (?-i)^\l OR %arranger% MATCHES (?-i)^\l OR "$meta(lyricist,0)" MATCHES (?-i)^\l OR "$meta(lyricist,1)" MATCHES (?-i)^\l OR %albumartist% MATCHES (?-i)^\l OR "$meta(artist,0)" MATCHES (?-i)^\l OR "$meta(artist,1)" MATCHES (?-i)^\l OR "$meta(artist,2)" MATCHES (?-i)^\l OR "$meta(artist,3)" MATCHES (?-i)^\l OR "$meta(artist,4)" MATCHES (?-i)^\l OR "$meta(conductor,0)" MATCHES (?-i)^\l OR "$meta(conductor,1)" MATCHES (?-i)^\l But, it is a good idea to get a small pillow, just before filtering a few tens of thousands of files. * * * 1. a-z ---
**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, 12:23pm UTC](https://community.mp3tag.de/t/how-to-filter-filenames-that-start-with-only-lowercase/13349/6 "2026-02-09T12:23:48Z")