Stefan Sperling <stsp_at_elego.de> writes:
> On Wed, Jun 15, 2011 at 06:11:31PM +0100, Philip Martin wrote:
>> peters_at_apache.org writes:
>>
>> > Author: peters
>> > Date: Wed Jun 15 16:43:24 2011
>> > New Revision: 1136114
>> >
>> > URL: http://svn.apache.org/viewvc?rev=1136114&view=rev
>> > Log:
>> > * configure.ac: Followup r1134219: Use 'cmp -s' instead of 'diff' to
>> > detect changes to svn_private_config.h. Take advantage of the fact
>> > that cmp -s produces no output even if a file does not exist.
>> > Use a temp variable to shorten the lines further.
>>
>> Is cmp as portable as diff? Is it always available with the same
>> behaviour? autoconf generates calls to diff, so we know that using diff
>> will work anywhere that autoconf works. As far as I can tell autoconf
>> doesn't use cmp.
>
>>From the cmp man page:
>
> HISTORY
> "A cmp command appeared in Version 1 AT&T UNIX."
>
> I would say that's ancient enough to be supported anywhere :)
Do they all support -s?
> Oh, and it also conforms to POSIX.
configure is supposed to work on anything that is "good enough". I
don't understand why we would choose to use cmp here, when diff is used
in the rest of the script.
--
Philip
Received on 2011-06-15 19:29:04 CEST