Chris Angelico <ros...@gmail.com>: > On Fri, Oct 6, 2017 at 7:09 PM, Steve D'Aprano > <steve+pyt...@pearwood.info> wrote: >> What are the right ways for a Python script to detect these sorts of >> situations? >> >> (1) Standard input is coming from a pipe; >> (2) Stdin is being read from a file; >> (3) Stdin is coming from a human at a terminal; >> >> I get these. How did I do? >> >> # 3 detect a terminal, hopefully with a human typing at it >> if os.isatty(0): >> print("Oy noddy, wake up and type something, I'm waiting for you!") > > This ought to be the only one that matters. It's the closest thing you > have to "we're working in interactive mode". Generally speaking, you > shouldn't care about the difference between a pipe and a file; and > remember, you can have stdin be anything else, too (eg a Unix or TCP > socket).
Generally, you shouldn't condition the program too much on such environmental details, although it is done. For example, the "ls" command outputs the directory listing in a (colorful) multi-column format when stdout is a terminal and in a (b/w) one-file-per-line format otherwise. Since such guesswork often goes wrong, the program should provide command-line options to specify the operating mode explicitly. The "ls" command has "--color" and "--format". The "ssh" command has "-o BatchMode=yes" and so on. Again, the Unix way is to preferably stay silent by default. If you want the program to chat, there is "--verbose". Marko -- https://mail.python.org/mailman/listinfo/python-list