Regular expression for valid filename

Question

I already gone through some question in StackOverflow regarding this but nothing helped much in my case.

I want to restrict the user to provide a filename that shoul

Answer 1

For full character set (Unicode) use ^[\p{L}0-9_\-.~]+$

or perhaps ^[\p{L}\p{N}_\-.~]+$ would be more accurate if we are talking about Unicode.

I added a '~' simply because I have some files using that character.