RFR: 8132541 : (process) ProcessBuilder support for redirection to discard output

[Martin Buchholz]

I approve the latest webrev.

But can't-stop-nitpicking Martin would write instead of

+         * The output may be discarded by writing to the operating
system specific
+         * <em>null</em> file.


"""A typical implementation discards the output by writing to an operating
system specific "null file"."""

And I'd have a chat with Alan about File#nullSink().


On Tue, Sep 22, 2015 at 6:27 AM, Roger Riggs <Roger.Riggs at oracle.com> wrote:

> Hi Martin,
>
> Please take another look?
> The language has been updated so it does not require discarding using a
> file.
>
> The URI of the webrev changed also:
>    http://cr.openjdk.java.net/~rriggs/webrev-discard-8132541/
>
> Thanks, Roger
>
>
>
>
>
> On 9/22/2015 2:52 AM, Martin Buchholz wrote:
>
>
>
> On Mon, Sep 21, 2015 at 11:28 AM, Roger Riggs <Roger.Riggs at oracle.com>
> wrote:
>
>> Hi Martin,
>>
>> On 09/21/2015 02:18 PM, Martin Buchholz wrote:
>>
>>
>> I'm not sure that all operating systems where Java may run will have such
>> a "null file" (does OS400?).
>>
>> True, but there are multiple ways to discard the output and it need not
>> be via the null file,
>> that's just easy on Unix and Windows.
>> The Redirect.file() method is allowed to return null and I've updated the
>> description to reinforce that for OS's that discard the output some other
>> way.
>>
>
> That seems to contradict what I see here:
>  +        /**
> +         * Indicates that subprocess output will be discarded.
> +         * The output is discarded by writing to the operating specific
> +         * <em>null</em> file.
> +         *
> +         * <p>It will always be true that
> +         * <pre> {@code
> +         * Redirect.DISCARD.file() the filename appropriate for the
> operating system &&
> +         * Redirect.DISCARD.type() == Redirect.Type.WRITE &&
> +         * Redirect.DISCARD.append() == false
> +         * }</pre>
> +         * @since 9
> +         */
> +        public static final Redirect DISCARD = new Redirect() {
>
> I think there will be confusion if the "null file" can be null.
>
>
>