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C--------------------------------------------------------------------------
subroutine ftgrec(iunit,nrec,record,status)
C Read the Nth 80-byte header record
C This routine is useful for reading the entire header, one
C record at a time.
C iunit i Fortran I/O unit number
C nrec i sequence number (starting with 1) of the record to read
C OUTPUT PARAMETERS:
C record c output 80-byte record
C status i returned error status (0=ok)
C
C written by Wm Pence, HEASARC/GSFC, June 1991
integer iunit,nrec,status
character*80 record
C-------COMMON BLOCK DEFINITIONS:--------------------------------------------
integer nb,ne
parameter (nb = 20)
parameter (ne = 200)
integer bufnum,chdu,hdutyp,maxhdu,hdstrt,hdend,nxthdr,dtstrt
integer nxtfld
logical wrmode
common/ft0001/bufnum(199),chdu(nb),hdutyp(nb),maxhdu(nb),
& wrmode(nb),hdstrt(nb,ne),hdend(nb),nxthdr(nb),dtstrt(nb),nxtfld
C-------END OF COMMON BLOCK DEFINITIONS-----------------------------------
integer ibuff,nbyte,endhd
character arec*8
if (status .gt. 0)return
C get the number of the data buffer used for this unit
ibuff=bufnum(iunit)
C calculate byte location of the record, and check if it is legal
nbyte=hdstrt(ibuff,chdu(ibuff))+(nrec-1)*80
C endhd=(hdend(ibuff)/2880+1)*2880
C modified this on 4 Nov 1994 to allow for blanks before the END keyword
endhd=max(hdend(ibuff),dtstrt(ibuff)-2880)
if (nbyte .gt. endhd .or. nrec .le. 0)then
C header record number is out of bounds
status=203
write(arec,1000)nrec
1000 format(i8)
call ftpmsg('Cannot get Keyword number '//arec//'.'//
& ' It does not exist.')
go to 100
end if
C position the I/O pointer to the appropriate header keyword
call ftmbyt(iunit,nbyte,.false.,status)
C read the 80 byte record
call ftgcbf(iunit,1,80,record,status)
if (status .gt. 0)then
write(arec,1000)nrec
call ftpmsg('FTGREC could not read header keyword'//
& ' number '//arec//'.')
return
end if
C update the keyword pointer position
nxthdr(ibuff)=nbyte+80
100 continue
end
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