CODE EXAMPLE FOR JAVASCRIPT

valid filename regex

/^(?!.)(?!com[0-9]$)(?!con$)(?!lpt[0-9]$)(?!nul$)(?!prn$)[^|*?:<>/$"]*[^.|*?:<>/$"]+$/

Must not be empty.
Must not start with .
Must not be com0-com9, con, lpt0-lpt9, nul, prn
Must not contain | * ?  : < > $
Must not end with .