Messages in this thread | | | Subject | Re: Linux 2.6 nanosecond time stamp weirdness breaks GCC build | From | Alexandre Oliva <> | Date | 02 Apr 2004 14:27:56 -0300 |
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On Apr 1, 2004, Ulrich Weigand <weigand@i1.informatik.uni-erlangen.de> wrote:
> - STAMP = echo timestamp > > + STAMP = sleep 1 >
I don't think this will fix the problem, at least not portably.
sleep 1 > filename
will truncate filename before sleep starts, modifying its timestamp at that point, and leave it unchanged afterwards. Some systems might update the timestamp again when the file truncated&opened for writing is closed, but I don't think this is required. Worse yet: some systems don't support empty files, and will error out because sleep 1 produced no output. Also, since some filesystems don't have 1-second granularity, you should probably use `sleep 2' instead.
A more portable way to spell it would be:
STAMP = sleep 2; echo timestamp >
or, in order to make $(STAMP) usable in the middle of &&/|| sequences:
STAMP = { sleep 2; echo timestamp; } >
-- Alexandre Oliva http://www.ic.unicamp.br/~oliva/ Red Hat Compiler Engineer aoliva@{redhat.com, gcc.gnu.org} Free Software Evangelist oliva@{lsd.ic.unicamp.br, gnu.org} - 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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