Sam Steingold <sds <at> gnu.org> writes: > > are you watching CLISP development? Nope. Should I be? :) > | m4_define([CL_DEFUN_CHECKER], > | [_$0([$]1, [$]2, [$]3, [$]4, [$]5, [$]6, [$1])]) > > interesting. > the above version is shorter and easier for me (and, more importantly, > those who will come after me) to understand, so I will stick with it. Good - the first approach is certainly more idiomatic in autoconf. I merely threw out the second approach for teaching purposes, based on the subject line; and I'm not at all heart-broken that you aren't using it (while writing my first reply, it took the most time and brain-effort to write the second approach, for the very reason that it is not very idiomatic). > | cl_program_xcheck=`cat <<\EOF > | AC_LANG_PROGRAM([#include <sys/socket.h> > | #include <X11/Xlib.h> > | #include <X11/Xauth.h>], > | [XauGetAuthByAddr(AF_INET,0,"",13,"localhost:0.0",13,"localhost:0.0");]) > | EOF` Bug on my part (and perhaps we need to update the manual) - not all shells behave the same when presented with incomplete here-docs: POSIX states that this is undefined: foo=`cat <<EOF ` since the ` occurs unquoted within a here-document. POSIX also requires that a here-doc end when the delimiter occurs on a line with a newline. But various shells interpret this differently: foo=`cat <<EOF hi EOF` ash claims that EOF is not on a line by itself, thus the here-doc is not terminated. bash claims that ` terminates the command substitution, and that a here-doc can end on end-of-input in addition to a newline. I agree with ash's interpretation that this is not the end of the here-doc, but that means that behavior is undefined, which means bash's behavior is also acceptable. On the other-hand, this should be well-defined by POSIX: foo=$(cat <<EOF hi EOF) EOF does not occur on a line by itself, so you could argue that a strict reading of POSIX says that particular ) should not terminate the command substitution because the contents of $() using that ) does not form a valid script. But again, ash is the only shell that rejected that. To be portable, you need: foo=`cat <<EOF hi EOF ` > > this expands to > ~ cl_clx_XauGetAuthByAddr_program=`cat <<\EOF Looks like inadvertant macro expansion in the variable name... > /* confdefs.h. */ > _ACEOF > cat confdefs.h >>conftest.$ac_ext > cat >>conftest.$ac_ext <<_ACEOF Oh well. It looks like stashing the program in a shell variable might not work (it certainly isn't as easy as I had thought it might be). But using an m4 macro to reduce duplication in your source should still be viable. -- Eric Blake _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
