使用 CodeBlocks IDE 读取 Fortran 文件时出现问题

Question

Recently, i've begun learning Fortran programmation language. I am using CodeBlocks IDE with GNU Fortran Compiler.

I have a problem in simple code that i found in a Fortran Course online that explains how to read and write from a file.

The program is the following:

program main
implicit none

character (len=14) :: c1,c2,c3
integer :: n
real :: T

open(unit=10,file='titi.txt')
read(10,*) c1,n,c2
read(10,*) c3,T
close(10)


open(unit=20,file='toto.txt')
write(20,*) c1,'il est',n,c2
write(20,*)'la',c3,'est de',T,'degres'
close(20)

end

Where the file 'titi.txt' contains:

bonjour 4   heures
temperature 37.2

The error message that appears in the console is the following:

 Program received signal SIGSEGV: Segmentation fault - invalid memory 
 reference.

 Backtrace for this error:
 #0  ffffffff

I tried using the flag

  -g

And than i found using the debugger that the problem is in the first line where 'read' was used

  read(10,*) c1,n,c2

I really don't know how to deal with this. The code seems pretty simple to me and i have never seen this error message before, so i don't know what does it mean.

Thanks for your answers in advance.

Answer 1

Thank you all for your responds. Actually what caused the problem is that i was using an old compiler. So when i downloaded the last version it all worked perfectly without changing any line in the code.

Answer 2

This is not an answer, but it's too much text for a comment.

It's running fine on my computer.

Can you compile it with

gfortran -g -O0 -fbacktrace -Wall -fcheck=all

That way you should get a lot more information. Also, you can add some error checking:

Add the following variables:

integer :: ios
character(len=100) :: iomsg

Then you can add error checking to all io statements like this:

read(10,*) c1,n,c2

becomes:

read(10,*,iostat=ios,iomsg=iomsg) c1,n,c2
if (ios /= 0) then
    print*, "Error reading c1, n, c2:"
    print*, trim(iomsg)
    STOP
end if

That can also give you some hints.