/^        # start of string
 0x       # 0x prefix
 [0-9A-F] # a hex digit
   {1,4}  #    1 to 4 of them
 $        # end of string
/xi       # x = allow spaces & comments in regexp
          # i = ignore case

[download]

or just /^0x[0-9A-F]{1,4}$/i

update: slight rewording to keep ww happy;)

In reply to Re: Regular expression for hexadecimal number by FunkyMonk
in thread Regular expression for hexadecimal number by isha

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