;+
; NAME:
;        TMPPRO
;
; PURPOSE:
;        Get the filename and path of a temporary .pro file.
;
; CATEGORY:
;        IO.
;
; CALLING SEQUENCE:
;
;        Result = TMPPRO( [Prefix, Ndigits] )
;
; OPTIONAL INPUTS:
;
;        Prefix:   The prefix of the filename, ('tmp'=default).
;
;        Ndigits:  The number of digits to append to the Prefix, (3=default).
;
; OPTIONAL INPUT KEYWORD PARAMETERS:
;
;        SEED:     The seed used by the random number generator to determine
;             the number to append to the Prefix.
;
; OUTPUTS:
;        The file specification returned is:
;
;             tmp_dir+Prefix+NNN+Suffix
;
;        where NNN is a random LONG integer with number of digits = Ndigits.
;        This routine also searches the tmp_dir for this filename. If a
;        duplicate filename is found, then another random number is chosen.
;
;        tmp_dir is the path to the <tmpprodir>/tmp directory 
;        where <tmpprodir> is the directory containing tmppro
;
;
; EXAMPLE:
;        Let's create a temp filename myNNNN.pro:
;
;             tmp_file = TMPFILE('my',4)
;
; MODIFICATION HISTORY:
;        30-DEC-2005    Modified from tmpfile by Leslie Young, SwRI
;        MODIFICATION HISTORY OF TMPFILE
;        Written by:    Han Wen, November 1994.
;        08-FEB-1995    Fixed minor bug, random integer -> random LONG integer
;        12-JUN-1995    Check existence of TMP directory and create it if no
;                       such directory exists.
;        01-JUL-1995    Use DIR_EXIST to check existence of TMP directory.
;        07-AUG-1996    Use TMPPATH (hacked version of FILEPATH) to determine
;                       TMP directory.
;-
function TMPPROPATH, FILENAME, ROOT_DIR=root_dir

         ON_ERROR,2                    ;Return to caller if an error
                                       ;occurs
;         findpro, 'tmppro', dirlist=dirlist, /noprint
;         if n_elements(dirlist) eq 0 then begin
;             root_dir = filepath('tmp',/tmp) 
;         endif else begin
;             root_dir = filepath('tmp',root=dirlist[0])
;         endelse

         res = routine_info('tmppro',  /source, /function) ; MUCH faster than findpro 
         tmppro_dir = strmid(res.path,0,strlen(res.path)-strlen(res.name+'.pro'))
         root_dir = filepath('tmp', root = tmppro_dir)
         return, filepath(filename, root=root_dir)
END

function TMPPRO, Prefix, Ndigits, SEED=Seed

         common TMPCOM, tmpseed

         NP = N_PARAMS()
         case NP of
              0    : begin
                        name      = 'tmp'
                        Ndigits   = 3
                     end
              1    : begin
                        name      = Prefix
                        Ndigits   = 3
                     end
              2    : begin
                        name      = Prefix
                     end
              else : message,'Invalid parameter, Ndigits='+$
                             string(Ndigits)
          endcase

          ext = '.pro'

         if KEYWORD_SET( SEED ) then tmpseed = SEED
         VERSION_OS = STRLOWCASE(STRMID(!VERSION.OS,0,3))

NEWRND:  numstr    = long( 10.^Ndigits * randomu(tmpseed) )
         numstr    = STRTRIM( numstr,2 )
         while (STRLEN(numstr) lt Ndigits) do $
            numstr = '0'+numstr

         ;    Make sure Temporary directory EXISTS
         ;    if it does NOT, then create it

         tmp_path  = TMPPROPATH('', ROOT_DIR = tmpdir)
         iss       = DIR_EXIST(tmpdir)
         if (iss eq 0) then begin
              message,'Creating a Temp directory...',/INF
              case VERSION_OS of
                   'vms' : spawn,'create/dir '+tmpdir
                   'win' : spawn,'md '+tmpdir
                   'mac' : print,'Not even! Get a real OS!'
                   else  : spawn,'mkdir '+tmpdir
              endcase
         endif

         filename  = name+numstr+ext
         fpath     = TMPPROPATH( filename )

         existfile = FINDFILE( fpath, COUNT=nexist )
         if nexist gt 0 then goto, NEWRND

         return, fpath
end