# Adding Leading Zeros to File, Album & Directory Names **URL:** \ **Category:** Support\ **Created:** [January 1, 2019, 9:40am UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066 "2019-01-01T09:40:19Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![sheepdisease](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepdisease](https://community.mp3tag.de/u/sheepdisease)\ **Post date:** [January 1, 2019, 9:40am UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/1 "2019-01-01T09:40:19Z")
Hello everyone, If I wanted to locate and rename file & album names which include 1-9 in the title for song numbers and albums with many discs, how would I first filter to show only those and secondly, add leading zeros without messing up the remainder of the file/album/directory names? I look forward to receiving your reply, thank you in advance. ---
**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:** [January 1, 2019, 3:24pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/2 "2019-01-01T15:24:57Z")
You can filter for fields with a single number with `%fieldname% MATCHES \d` To rename files and folders it is advisable to get the data in the tag fields correct and then rename the files. Please note that a number of characters are invalid for filenames or folders. You can rename files and folders with actions of the type "Format value" or the functions in the Convert menu. ---
**Author:** ![sheepdisease](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepdisease](https://community.mp3tag.de/u/sheepdisease)\ **Post date:** [January 1, 2019, 7:16pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/3 "2019-01-01T19:16:02Z")
Thank you for your reply. Let's use an example, there are two that I can think of. The first is Now That's What I Call Music. I changed the track names so that they include the track number with no leading zero, then the song name, followed by the artist name in brackets. I then change the artist name in the artist and artists field from the true artist to Now That's What I Call Music because when I haven't done this in the past it has messed up my folder structure in Windows Media Player. In this example, I would like to add a leading zero to the file name without adding a leading zero to the track number. I would also like to make sure that Vol. 02 appears this way, if it doesn't have a leading zero then one should be added. At the same time, I would need to avoid adding a leading zero to the Disc number. The same would apply to the directory. ![image](https://community.mp3tag.de/uploads/default/original/2X/0/0ec7972c683a792f8348599aa8d23ff66394bc40.png) Once this has been figured out I will mention the second example. Thanks for your help. ---
**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:** [January 1, 2019, 7:21pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/4 "2019-01-01T19:21:30Z")
You can create a new filename (without touching the data in the tag fields) with: Convert\>Tag-Filename Format string: `$num(%track%,2)_%title%` (I would recommend a character other than the space character to separate the fields, e.g. the underscore. If you do not like it, the use whatever you want) ---
**Author:** ![sheepdisease](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepdisease](https://community.mp3tag.de/u/sheepdisease)\ **Post date:** [January 2, 2019, 6:49pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/5 "2019-01-02T18:49:51Z")
Thanks for your reply, going back a step to get the filter right, how do I filter for 1-9? Take the filename for example, how do I make it match files with 1-9? %\_FILENAME% MATCHES \d ---
**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:** [January 2, 2019, 6:58pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/6 "2019-01-02T18:58:27Z")
Have you tried it? I mean: typing your post takes longer than testing it in MP3tag. ---
**Author:** ![sheepdisease](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepdisease](https://community.mp3tag.de/u/sheepdisease)\ **Post date:** [January 2, 2019, 7:00pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/7 "2019-01-02T19:00:24Z")
Yes I did try it first, it came up with no results when there were loads of files with 1-9 in the filename. Trying %\_FILENAME% MATCHES 0\d instead brought up more likely results but also numbers from 10+ and not all tracks numbered 1-9 in the filename. ![image](https://community.mp3tag.de/uploads/default/original/2X/7/76da61966fc9f5d7a87a28f5b2d212feef559b6c.png) Considering that there are 182 discs, there should be 1,638 tracks found with the filter. ---
**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:** [January 2, 2019, 7:08pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/8 "2019-01-02T19:08:40Z")
If you want to filter for a number at the beginning, use `..... MATCHES "^\d"` If you want to filter for a single number at the beginning which is followed by a space character, use `..... MATCHES "^\d "` the dots stand for the fieldname. All this and more is revealed in the help > **[Filter and Search – Mp3tag Documentation](https://docs.mp3tag.de/filter/)** > > Documentation on Filter and Search and keywords to form complex filter expressions. Mp3tag is the universal Tag Editor. ---
**Author:** ![sheepdisease](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepdisease](https://community.mp3tag.de/u/sheepdisease)\ **Post date:** [January 2, 2019, 7:27pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/9 "2019-01-02T19:27:12Z")
Thank you, %\_FILENAME% MATCHES "^\d " works well. I will go back to testing. ---
**Author:** ![sheepdisease](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepdisease](https://community.mp3tag.de/u/sheepdisease)\ **Post date:** [January 2, 2019, 9:13pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/10 "2019-01-02T21:13:54Z")
That works well. Filter %\_FILENAME% MATCHES "^\d " Action Format value \_FILENAME Format string $num(%track%,2) %title% ---
**Author:** ![sheepdisease](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepdisease](https://community.mp3tag.de/u/sheepdisease)\ **Post date:** [January 3, 2019, 7:38pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/11 "2019-01-03T19:38:12Z")
Is it possible to filter by a number of words, which are listed and case sensitive? For example, I want to check that words such as 'the', to' and 'at' are lower case so I would like to find any which are upper case 'The', 'To' and 'At' so that I can correct it. ---
**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:** [January 3, 2019, 7:43pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/12 "2019-01-03T19:43:52Z")
`%title% MATCHES "(?-i) The"` filters for " The" ---
**Author:** ![sheepdisease](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepdisease](https://community.mp3tag.de/u/sheepdisease)\ **Post date:** [January 3, 2019, 7:48pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/13 "2019-01-03T19:48:52Z")
Brilliant, thank you. Is it possible to combine several so it searches for one or more like the examples I listed within one filter query? ---
**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:** [January 3, 2019, 7:50pm UTC](https://community.mp3tag.de/t/adding-leading-zeros-to-file-album-directory-names/44066/14 "2019-01-03T19:50:21Z")
see the help on the filter options: > **[Filter and Search – Mp3tag Documentation](https://docs.mp3tag.de/filter/)** > > Documentation on Filter and Search and keywords to form complex filter expressions. Mp3tag is the universal Tag Editor. (which I linked before) Have a look at the descriptions for AND, OR and NOT ---
**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/adding-leading-zeros-to-file-album-directory-names/44066/15 "2026-02-09T12:27:50Z")