C This file: http://ftp.aset.psu.edu/pub/ger/fortran/hdk/enter.for
C
      DOUBLE PRECISION X(5)
      CHARACTER*80 STRING
      DO 1 I=1,10
C---For PC Watfor77: pressing
C   only Ctrl-Z followed by pressing Enter will take the END= branch.
        READ(5,2,END=99) STRING
2       FORMAT(A)
C---To use this heuristic with numeric data, first read STRING then
C   read from that STRING if it is not "Only Blanks and or Enter Key"
        WRITE(6,*) 'Record # ',I,' read.'
        IF(STRING.EQ.' ') THEN
          WRITE(6,*) 'Only Blanks and/or Enter key'
        ELSE
C---Initialize numeric array X to -Infinity so that if not 5 (in this
C   case) values are entered, the remaining values of the array will
C   retain the "-Infinity" value given here. This code could be moved
C   to the begining of the DO 1 loop so that all of the array X would
C   be "-Infinity" when only blanks and/or the Enter key was pressed.
          DO 3 J=1,5
3         X(J)=-1.D-75
          READ(STRING,*,END=4) X
4         WRITE(6,*) X
        ENDIF
1     CONTINUE
99    WRITE(6,*) I-1,' Records read.'
      STOP
      END