-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Asking the list reaches a larger knowledge base than asking one developer. I think there may already be version comparison macros out there, but I have not tried searching for one. They probably involve invoking test multiple times over each version number component, rather than trying to combine the version components into a single number. But, if you really want to do it with arithmetic, I think something like this is portable (provided expr is not implemented with 16-bit math, which would overflow): `expr $major \* 1000000 + $minor \* 1000 + \$patch` My original post on the topic was here: http://lists.gnu.org/archive/html/autoconf/2004-12/msg00180.html According to Mark Asbach on 2/23/2005 2:24 PM: > Hi Eric, > > searching for portable arithmetic constructs in autoconf macros, I found > a post of yours ("Proposed doc updates"), that seems to mention, what I > need: > >> address@xxxxxxxxxxxxxxxxx $((@var{arithmetic})) >> +Posix specifies that this construct will evaluate its contents as an >> +arithmetic expression, with the value of the expression being the >> +result. However, Ash treats this as an undocumented quoting mechanism, >> +resulting in the literal expression surrounded by 8-bit markers and an >> +indication of the current quoting level. Likewise, the >> address@xxxxxxxxxxxxxxxxx/bin/sh} of Solaris 8 does not support it: > > > However, the necessary details are missing from your post and I couldn't > find parts of the text anywhere else (searching with Google). > > Could you please give me a hint on how to do portable math inside > autoconf m4 macros? My problem looks simple, but the only solution I > found was using "$((expression))" constructs, that - as you state - are > not portable. I have a string containing a dotted version number > "1.3.23" that I need to compare to some other number like "1.3.20". > Currently, I split at the dots and then recombine as 1000000*major + > 1000*minor + subminor, then I can compare with 'test'. But how to do > that in a portable way? > > Mark > > > - -- Life is short - so eat dessert first! Eric Blake ebb9@xxxxxxx -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFCHdB384KuGfSFAYARAoxzAJ4qKSVLcMxhXepI+sm8BZcCt6bdyQCfayEy j6rykJLq9y13eFk4dNln1XA= =15AA -----END PGP SIGNATURE----- _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
