program read_csv
implicit none
integer, parameter :: dbl = selected_real_kind(p=14, r=99)
integer :: iost=0
integer :: I1, I2, I3
real(dbl) :: R1, R2, R3
character(80) :: text
character(90) :: line="------------------------------------------------------------------------------------------"

!Character formats
1  format (A)
2  format (/A/)
3  format (A/)
4  format (/A)
!Combined format
10 format (I8,3ES16.8,2I8)

open (unit=1, status="old", file="text.in", action="read")

print 4, line
print 3, "CASE 1"
print 3, "Read numbers from file into int/real variables:"
print 1, "Results:"
print 1, "      I1              R1              R2              R3      I2      I3"
read_loop_1: do
  I1=-99;       I2=-99;       I3=-99
  R1=-99._DBL;  R2=-99._DBL;  R3=-99._DBL
  read(1,10,iostat=iost) I1, R1, R2, R3, I2, I3
  if ( iost /= 0 ) then
    if ( iost < 0 ) then
      print 4, "End Of File Reached"
      print 3, line
    else if ( iost > 0 ) then
      print *, "ERROR reading in CASE 1:  iost = ", iost
    end if
    exit read_loop_1
  else
    print 10, I1, R1, R2, R3, I2, I3
  end if
end do read_loop_1

rewind (1)

print 4, line
print 3, "CASE 2"
print 3, "Read numbers from file into string and then read from string into int/real variables:"
print 1, "Results:"
print 1, "      I1              R1              R2              R3      I2      I3"
read_loop_2: do
  I1=-99;       I2=-99;       I3=-99
  R1=-99._DBL;  R2=-99._DBL;  R3=-99._DBL
  read(1,1,iostat=iost) text
  if ( iost /= 0 ) then
    if ( iost < 0 ) then
      print 4, "End Of File Reached"
      print 3, line
    else if ( iost > 0 ) then
      print *, "ERROR reading in CASE 2:  iost = ", iost
    end if
    exit read_loop_2
  else
    read(text,10,iostat=iost) I1, R1, R2, R3, I2, I3
    print 10, I1, R1, R2, R3, I2, I3
  end if
end do read_loop_2

rewind (1)

print 4, line
print 3, "CASE 3"
print 3, "Read numbers from file into string and then read from string into int/real variables:"
print 3, "Add condition that if formatted read fails, then do list-directed read using *"
print 1, "Results:"
print 1, "      I1              R1              R2              R3      I2      I3"
read_loop_3: do
  I1=-99;       I2=-99;       I3=-99
  R1=-99._DBL;  R2=-99._DBL;  R3=-99._DBL
  read(1,1,iostat=iost) text
  if ( iost /= 0 ) then
    if ( iost < 0 ) then
      print 4, "End Of File Reached"
      print 3, line
    else if ( iost > 0 ) then
      print *, "ERROR reading in CASE 3:  iost = ", iost
    end if
    exit read_loop_3
  else
    read(text,10,iostat=iost) I1, R1, R2, R3, I2, I3
    if ( iost /= 0 ) then
      read(text,*,iostat=iost) I1, R1, R2, R3, I2, I3
    end if
    print 10, I1, R1, R2, R3, I2, I3
  end if
end do read_loop_3

print 2, "NORMAL TERMINATION"

close (1)
end program read_csv