Need help defining Fortran 77 input/output streams using g77!

Gethyn · 08-14-2003, 11:07 AM

I'm currently trying to compile some fairly old VAX Fortran 77 code using g77. It all seems to be working except for one big problem: the program relies on input/output streams linked to files. I'm afraid I know very little about Fortran, but I believe this is referred to as an input/output unit - each file is associated with an integer, and then when the file is written to/read from, the Fortran code merely refers to the number (in exactly the same way that '5' is the unit for standard input and '6' is for standard output). Sorry if you feel I'm insulting your intelligence, I'm trying to get it straight in my head!
My big problem is, I don't know how to assign the file paths/names to the units. Is this done inside the program listing, or inside the Makefile, or both? What's the syntax?

This is probably a very simple question, but I'm not a Fortran programmer myself (I write C++ usually!) and I've found it totally impossible to discover the answer on the net or in the manual...

Your help would be greatly appreciated!

kev82 · 08-14-2003, 12:42 PM

hopefully this gives the general idea, it attaches unit 10 to /tmp/file, writes Hello to it, then closes it.

Code:

open(10,file='/tmp/file')
write(10,*) 'Hello'
close(10)