Regex matching date pattern

Question

I want to match filenames with date format and ANY extension . Is following regex good for this:

[0-9]{2}.[0-9]{2}.[0-9]{4}(?:\..*)?

??

Above regex, although seems to work, does not return this string in result: "12.1.1990.txt" How to write regex which also includes dates like either

12.12.2203.bmp
or
1.11.2005.txt
or
12.1.2006.bin
?

Thanks. And ps. where to find further info on writing these expressions?

Answer 1

You can use this regex:

^[0-9]{1,2}\.[0-9]{1,2}\.[0-9]{4}(?:\..*)?$

RegEx Demo

Answer 2

尝试这个 -

[0-9]{2}.[0-9]**{1,2}**.[0-9]{4}(?:\..*)?

Answer 3

I'd go for this regex:

\d{1,2}.\d{1,2}.\d{4}(?:\.\w*)?

Also, I'm using some online regex tools for checking my regex, which is very handy on checking specific things (not to advertise or anything).

By this website, FileExt , DOS illegal characters in file extension are this: |<>\\^=?/[]";* plus control characters, so changing the file extension regex to this one: (?:\\.[^\\|\\<\\>\\\\\\^\\=\\?\\/\\[\\]\\"\\;\\*\\.]*)? will match valid file extensions.

The final regex would be: \\d{1,2}.\\d{1,2}.\\d{4}(?:\\.[^\\|\\<\\>\\\\\\^\\=\\?\\/\\[\\]\\"\\;\\*\\.]*)?

Regex101