title: Program received signal SIGSEGV while reading a file
body: <p>I want to read a file named pvt.txt and just print it to the screen. But when the program runs it always showed "Program received signal SIGSEGV: Segmentation fault - invalid memory reference."</p>
  
  <p>It's a fortran 90 code, just a simple code but always showed error like that. I can write a file, but I can't read it in the program. I just write a simple code to try, but it still doesn't work.</p>
  
  <p>the file pvt.txt is located in the same folder with the program.</p>
  
  <pre><code>program reservoir_sim
      implicit none
  
       integer a, b, c
  
       open(unit=10, file='pvt.txt')
  
          read(10,*) a, b, c
  
          print*, a, b, c
  
       close(10)
  
  end program reservoir_sim
  </code></pre>
  
  <p>In the pvt.txt file's just wrote "1, 2, 3", but it still doesn't work</p>