pro read_uf_rec,lun,rec_len,buffer
;==================================================================
;
; Written by S. D. Mayor in April 1996 to read blocked UF records.
;
; INPUT: LUN........... logical unit number to read from
; OUTPUT: REC_LEN...... number of bytes of data between markers
;         BUFFER....... a byte array of length REC_LEN
;
; This subroutine reads a record from a file that has already been
; opened for reading under logical unit number LUN.  This subroutine 
; expects to see a 4-byte marker before and after the actual record.
; The 4-byte marker contains ; the number of bytes in between them.
;
;==================================================================

marker = bytarr(4)
readu,lun,marker
rec_len=long(marker,0)
;print,'rec_len = ',rec_len
buffer = bytarr(rec_len)
readu,lun,buffer
readu,lun,marker
return
end