How do I check if a given string is a legal/valid file name under Windows?

Question

I want to include a batch file rename functionality in my application. A user can type a destination filename pattern and (after replacing some wildcards in the pattern) I n

Answer 1

Windows filenames are pretty unrestrictive, so really it might not even be that much of an issue. The characters that are disallowed by Windows are:

\ / : * ? " < > |

You could easily write an expression to check if those characters are present. A better solution though would be to try and name the files as the user wants, and alert them when a filename doesn't stick.