Stefan Sperling <s...@elego.de> writes: > On Wed, Jun 15, 2011 at 06:11:31PM +0100, Philip Martin wrote: >> pet...@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
