Will McDonald wrote: > On 23/01/06, Diez B. Roggisch <[EMAIL PROTECTED]> wrote: >> > I can get the script to behave as expected when content's piped to it >> > using sys.stdin but I'd like to know that there's data coming from >> > stdin or fail and print the useage again. Is there a simple way to >> > achieve this? >> >> There are more experienced UNIXers here, but from my POV I don't see how >> that can happen. The reason is simply that >> >> - sys.stdin alwasy exists (unless you close it yourself) >> >> - in a pipe (which this essentially is) there is now way to know if >> there >> is more date to come or not, except for the "broken pipe" error - but >> that won't happen to you, as sys.stdin is not broken just because there >> is currently no data arriving. > > That's a good point. I did wonder if it'd just have to sit there > waiting for input much like cat would. I think that's preferable, and > simpler :), than implementing timeouts. > In unix you can always use select.select() on files and pipes as sys.stdin is. Use a timout-value of 0 and you get the 'ready-state' of the file descriptor i.e. the presence of waiting input-data.
Peter -- http://mail.python.org/mailman/listinfo/python-list
