Curiosity - File Content Determination?

[Intel_C_Intel]

I have some FORTRAN code that opens a file with FORM = 'FORMATTED', STATUS = 'UNKNOWN', RECL = 1024, CARRIAGECONTROL = 'LIST'. I write out some formatted records.

I can open my file in Notepad, which seems happy that the content it text (or at least, can be displayed as text).

If I use DevStudio to try to open the file, specifying the type as Text, DevStudio claims the file is binary and won't open it (it will open it as binary).

If I then open the file in Notepad, save it and close it, I can then open it in DevStudio as text.

I checked and the file does not change size in any way, even by a byte. So how does DevStudio determine the type of the contents of a file? And why does it 'get it wrong'?

Of course, Notepad is probably displaying a binary file as text (as it always tries to do), it just so happens that the binary is text...

[Steven_L_Intel1]

My recollection is that DevStudio looks to see if there non-printing characters in the file. I'd want to see the actual file (before NOTEPAD) before commenting further - can you attach a ZIP archive of an example?

Steve

[Intel_C_Intel]

Steve, you're right, my original file has some NULL characters in it, which are replaced with spaces when saved from notepad. Seems odd because they result from the line:

WRITE (filun, 1000) in_field

where

1000 FORMAT (6(A,','))

(in_field is a CHARACTER*16 array, width = 18)

The same formatting line is used elsewhere and does not output NULLs. E.g.:

WRITE (filun, 1000) in_unit

where in_unit is a CHARACTER*10 array).