Fortran 90错误：输入需要太多数据

Question

I have the following code:

if (complex) then
read(unitvector) (CoefC(jl),jl=1,NV)
endif

Where a user indicates if the data is a collection of complex numbers. Now, if the user indicates that it is, but it actually isn't, i get error 67 (input requires too much data). How can i trap that, so i can write that perhaps a user made a mistake. I was thinking it would look something like:

read(unitvector, ioStat=iocplx) (CoefC(jl),jl=1,NV) 

but where would i put the "if" to check for the error?

Answer 1

That depends on the overall logic of the program, we cannot tell you the best way for you from such small code snippet. You can try something like (not tested):

if (complex) then
  read(unitvector, ioStat=iocplx) (CoefC(jl),jl=1,NV) 
  if (iocplx/=0) stop "Error reading the complex data."
end if

or

if (complex) then
  read(unitvector, ioStat=iocplx) (CoefC(jl),jl=1,NV) 
  if (iocplx/=0) then
     write(*,*) "Error reading the complex data, triung real."
     complex = .false.
     backspace(unitvector)
     read(unitvector, ioStat=ioreal) (CoefR(jl),jl=1,NV)
     if (ioreal/=0) then
       stop "Error reading real data."
     end if
  end if
end if

But you really did not specify what you want, stop the program and write a meaningful message? Read data some other way? Everything is possible and we do not have a crystal ball.