On Thu, 2006-02-02 at 13:52 +0000, E. Rosten wrote: > > How can I make sure user has at least gcc4 installed? > > (after establishing that the compiler is gcc), and doing AC_PROG_AWK: > > version=`$CXX -v 2>&1 | $AWK -F'[ .]' '/version/{print $3}'` > > should do the job. There are some reasons for doing this Nope, I can not imagine any reason justifying this approach. This approach is broken (I prefer to call it naive), because a) version strings are subject to change at any time by vendors. => You will always find situations, where your version check will fail somewhere. b) version strings are not at all connected to a compiler providing a feature, because vendors apply patches, enable/disable features. So even if you believe to be using "GCC-4.0.2", it is very likely to behave different from a vanilla FSF-GCC-4.0.2 and from other vendor incarnations of "GCC-4.0.2". This becomes crucial, if you try to apply version checks to work around bugs - The GCC-4.0.2 you are using might be in trouble, but this doesn't mean other vendors' GCC-4.0.2 are having the same issue. > (bigish changes > in standards compliance in g++ 4 compared to g++ 3), Then you should write an autoconf compile-check to check whether the compiler is subject to such changes - better, write your code in such a way that you won't have to resort to autoconf checks. > but you should > probably check to see if you're not being overly restrictive before > implementing this test. Consult google for KDE blacklisting certain versions of GCC-4.0. They fell into the trap of applying the approach you are proposing. Ralf _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf