How to write mine regular?

html5syt

I use fof/upload,but when I upload non-image file like pdf,I receive that "not support.". And I find it's caused by mine regular.But how to write it?😭

I want 3 type:

all image can show directly in posts.
the non-image file show donload button
.txt text file show preview.

GreXXL

html5syt

^image\/.* and Complete Image Preview Template displays uploaded images.
(application\/(x-(7z|rar|zip)-compressed|zip|arj|x-(bzip2|gzip|lha|stuffit|tar)|pdf)) and Default Download Template will allow uploading and sharing compressed files and pdfs.
^text\/.* and Text Preview you can upload any plain text file and display it.