--
--Unique File Names
--
--jxliv7@hotmail.com (jon)
--
--uniquefilenames.e
--
--Ver 1.1
--

--The created filename will be 8 characters long.
--The filename character set is A-Z.
--The intent is to be 8.3 compatible.

--After looking at CChris's "unique_filename() function", I realized that
--	if filenames were based upon time (consistently for any one
--	application), then each filename would also be unique.

--These unique filenames are based upon the Euphoria date() function,
--	which means there can only be ONE unique filename per second.
--If you need multiple files per second, use a "for" function to add
--	characters to the end of the filename.

--You could add a character(s) to the beginning or end of the filename,
--	but this character set will only be unique every second.
--You may also add any extension you choose (or none).

--There are two caveats: you can't generate more than ONE filename per
--	second, and a filename by the created name could possibly exist
--	(although the possibly is rather remote).

--Revised 2007-03-31 
--Corrected error, used base 27 in calculations instead of 26. Oops.
--Instead of a new filename every second, it was 25 seconds.
--Thanks to c.k.lester for the bug report.

--Comments, suggestions, questions, etc., are appreciated.


--
global function UniqueFileNames()

sequence Filename, curTime

integer N, C, Tot


Filename = "zzzzzzzz"	--if there's a lower case "z" in the filename,
			--	there's an error
curTime = date()

N = 4
C = 390625		--390625 = 25^4. in base 26 A=0, B=2, .., Z=25

Tot = curTime[4]*3600 + curTime[5]*60 + curTime[6]
			--these are the elapsed seconds so far in the day

Filename[1] = curTime[1] - 107 + 65
			--2007 is 107 in date(), so the first character is
			--	"A" (ASCII 65) -- in 2008 it woud be a "B"
			--if you'd like, you could change this

Filename[2] = floor(curTime[8]/25)
Filename[3] = 65 + curTime[8] - (Filename[2] * 25)
Filename[2] += 65
			--curTime[8] is the day of year, 1 thru 365 or 366
			--for example, day 1 = AB, 267 = JQ, and 365 = NO

			--this loop converts the time of day in seconds
			--	to a 5 digit, base 26 number
while N-9 do
	Filename[N] = floor(Tot/C)
	Tot -= (Filename[N]*C)
	Filename[N] += 65
	N += 1
	C /= 25
end while

return Filename		--a unique 8 character filename using only A thru Z

end function
--