subroutine dtcrdappt (eofflg, indflg)

c search through appointment files for entries matching range of hash values.
c opens files if EOFFLG set on entry. INDFLG controls whether indirect files
c should be opened as encountered, and whether caller wants to look at indirect
c entry or not:

c	INDFLG
c	  -1	No processing @
c	   0	Normal processing
c	  +1	Return before opening @

c	EOFFLG  Entry			Exit
c	  -1	Initialize		EOF return
c	   0	Normal re-entry		Normal return, valid entry
c	  +1	Open @ file		Return for @ filename found

c Processes both old- and new-format files
c	Old: yymmddhhh appt (possibly no blank between HHH & APPT)
c	New: yyyymmddhhhh appt

c Created 19850802, CG, using some code removed from DAY subroutine

	implicit none

	integer eofflg, indflg		! i/o, i only

	include 'comdtc.inc/nolist'
	include 'apptdtc.inc/nolist'
	include 'defcentry.inc/list'	! Default century for old format

	character*1 nullch /0/		! Old old files had trailing NULs

	integer i, ij, lth, istrend, nunit

	include 'stmtfunc.for/nolist'

c Begin code

c ***	type 950, irqhash
c 950	format(2z9.8)

	if (eofflg .lt. 0)			! Start scan
	1 then

	    nunit=1
	    close(1)
	    Open (unit=nunit, file=FNAME, status='OLD',
	1	  form='FORMATTED', readonly, err=99)

	    eofflg = 0
c ***	type  *, ' Opened file'
	end if

c loop back up here to continue reading and processing input file:

	do while (eofflg .ge. 0)

 900	format(q, a)			! Read all
 901	format(3i2, i3)			! Decode old
 902	format(i4, 2i2, i3)		! Decode new

	    if (eofflg .gt. 0)		! must open indirect file
	1     then

		eofflg = 0

c ***	type 951, work(istart)
c *** 951	format (' ', a)

		nunit = 2
		close(2)
		Open (unit=nunit, file=work(istart), status='old',
	1	      form='formatted', readonly,
	2	      carriagecontrol='LIST', err=1067)

	    end if
	
	    read (nunit, 900, end=400), lth, workstr
c ***	type  *, ' ', workstr
	    do i = min0(lth, iwrkln), 1, -1
		if ((workstr(i:i) .ne. ' ')		! Look for non-blank
	1	    .and. (workstr(i:i) .ne. nullch))	! & non-null
	2	go to 10				! Break
	    end do

	    i = 1					! All blank entry ???

 10	    lth = i

c String is filled with blanks regardless of length of record
	    
	    if (chnumeric(workstr(10:10)))
	1     then			! new format
		read(workstr, 902, err=30) ihy, ihm, ihd, iht
		istart = 12		! Index of first valid character
c ***	type  *, ' New format'

	      else			!	Old format

 30		continue		!	Retry old

		read(workstr, 901, err=300) ihy, ihm, ihd, iht
		ihy = ihy + icntry	!	Insert current century

		istart = 10		! Assume old, old format

c ***	type  *, ' Old format'

	    end if			! (workstr(10) is numeric)

	    if (workstr(istart:istart) .eq. ' ')
	1	istart = istart + 1	! Index of first valid character

	    iwkln = max0((lth - istart) + 1, 1)
	    istrend = (istart + iwkln) - 1
	    iaptln = max0(min0(iwkln, icmln), 1)

	    if (ihm .eq. 99)
	1     then

		ihy = 9999		! set all fields
		ihd = 99
		iht = 999

		if ((indflg .ge. 0) .and. (nunit .eq. 1))
	1	  then

		    call fnscan(work(istart), icmln - istart + 1,
	1			iwkln, ij)	! Common code to check filename

		    if (ij .ne. 0)
	1	      then			! Skip if no file

c ***	type *, ' IJ = ', ij
			eofflg = 1

			if (indflg .gt. 0)
	1		  then

			    apptstr = workstr(istart:istrend)

			    return	! DAY, STRIP want a look

			end if		! Found 1

		    end if		! non-null file-name

		end if			! valid place for indirect

	      else		! not filename flag in record

		irchash = ihymd(ihy, ihm, ihd)	! Compute hash for record

c ***	type 950, irchash

		if ((irchash .ge. irqhash(1))
	1	    .and. (irchash .le. irqhash(2)))
	2	  then			! Found record within range, exit

		    apptstr = workstr(istart:istrend)

c ***	type *, ' Returning'

		    return				! Break out of loop

 400		    continue	! no more appointments left in file.
c ***	type  *, ' EOF'

		    if (nunit .eq. 1)		! Which file were we reading?
	1	      then

			eofflg = -1		! real end of file

		      else

 1067			close (2)		! Error opening indirect file

			nunit=1

		    end if		! Which unit had EOF

		end if			! Hash range test

	    end if			! type of record

 300	    continue		! Error decoding y/m/d/t fields

	end do			! Read next line from current file

	close (1)		! Close first-level

 99	continue		! Failed first open

	end