Is it a text or binary file?

Hello gurus,

I would like to know the following:

If I have to open a file (with 'OPEN DATASET [...]'), how do I know whether it is a text or a binary one?

If it is a text one, I have to perform some tasks; and if it's a binary one, I have to do others.

I think a command in Tx. 'SM69' could be used but... Isn't any other easier way available?

Thanks a lot!,

Eloi