Messages in this thread | | | Date | Sun, 30 Apr 2006 14:10:48 +0200 | From | Pavel Machek <> | Subject | Re: led_class: storing a value can act but return -EINVAL |
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Hi!
> > Well, I'd argue current behaviour is okay... can you strace it? It > > should accept the number (return 3) then return -EINVAL. > > That's exactly what happens.
And that's pretty much exactly okay.
You got success return when you wrote "255" there, then you got -EINVAL when you tried to put newline there. Expected behaviour, I'd say.
...I can see it looks ugly when you do echo manually, but you simply should not do that.
> Which is totally bogus, because userspace will think that the setting > didn't succeed. Or application authors will ignore the return value > assuming that it always succeeded. Or read the value back to see if it > succeeded. All icky, when we can well have a good return value.
Well, they got what they deserve, that \n does not belong there. And they _did_ get success report -- "3" was returned. That's how unix works, I'd say. Educate userspace authors that adding \n is bad idea.
Pavel -- Thanks for all the (sleeping) penguins. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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