How to handle blank in formatted integer input - fortran

Question

I have a file like this
1980 01 23
1982 04 30
1983 05 22
1984
1985 02 11
I tried to read data using format "(3I4)"
implicit none
integer, parameter :: FUnitIn = 10
character(len=255) :: FNameIn = "./test.txt"
integer :: FStatOpen, FStatRead
integer :: yyyy, mm, dd
open ( unit = FUnitIn, &
file = trim(FNameIn), &
access = "sequential", &
form = "formatted", &
status = "old", &
iostat = FStatOpen)
if (FStatOpen /= 0) then ! ERROR
stop
end if
do
read (FUnitIn, "(3I4)", iostat=FStatRead) yyyy, mm, dd
if (FStatRead /= 0) then
exit
else
write (6, "(3I4)") yyyy, mm, dd
end if
end do
I got three zeros for the blank line.
Are there any options to handle blank input?

Answer 1

You can read each line in a character variable, and check its adjusted-trimmed length if your sole goal is to skip the empty line, something like the following code (see variable record). Going beyond this simple implementation requires some extra information from you as to what behavior exactly you want to get.
implicit none
integer, parameter :: FUnitIn = 10
character(len=255) :: FNameIn = "./test.txt"
integer :: FStatOpen, FStatRead
integer :: yyyy, mm, dd
character(len=1023) :: record
open ( unit = FUnitIn, &
file = trim(FNameIn), &
access = "sequential", &
form = "formatted", &
status = "old", &
iostat = FStatOpen)
if (FStatOpen /= 0) then ! ERROR
stop
end if
do
read (FUnitIn, "(3I4)", iostat=FStatRead) record
if (FStatRead /= 0) then
exit
elseif ( len_trim(adjustl(record)) > 0 ) then
read (record, *) yyyy, mm, dd
write (6, "(3I4)") yyyy, mm, dd
end if
end do