I think you are correct, and this is now in git commit 8992c19 with one addition: set SED if it is not previously set. In other words, this line: test -n "$SED" || SED=$ac_path_SED
On Fri, Oct 26, 2012 at 12:34 PM, Robert William Fuller < hydrologiccy...@gmail.com> wrote: > Consider the following code in configure.ac: > > SED_EXTENDED_RE_FLAG='-r' > result=$(echo 'define' | $ac_path_SED -r -e 's/^define/foo/' 2>/dev/null) > if [[ $? -ne 0 ]] ; then > result=$(echo 'define' | $ac_path_SED -r -E 's/^define/foo/' > 2>/dev/null) > if [[ $? -ne 0 ]] ; then > SED_EXTENDED_RE_FLAG='-E' > else > AC_MSG_WARN([Don't have SED that understand extended RE's. Some minor > compilation issues may fail.]) > SED_EXTENDED_RE_FLAG='' > fi > fi > > Now consider that the second test ought to be [[ $? -eq 0 ]] because we're > checking to see if the -E flag works. BUT, the second invocation of sed > will never succeed because the -r and the -E flag are mutually exclusive. > One exists on one platform and not the other. So the second run of sed > really ought to be "-E -e" not "-r -E". (I suspect that someone > accidentally changed the wrong option during a copy and paste of the prior > invocation when they wrote this code originally.) > > Supposing we make all these changes, this still won't work on MacOS > because it has ac_path_SED set to /usr/X11/bin/gsed which does not exist. > We should use the SED variable rather than ac_path_SED. So when all is > sed and done, it should look like this: > > SED_EXTENDED_RE_FLAG='-r' > result=$(echo 'define' | $SED -r -e 's/^define/foo/' 2>/dev/null) > if [[ $? -ne 0 ]] ; then > result=$(echo 'define' | $SED -E -e 's/^define/foo/' 2>/dev/null) > if [[ $? -eq 0 ]] ; then > SED_EXTENDED_RE_FLAG='-E' > else > AC_MSG_WARN([Don't have SED that understand extended RE's. Some > minor compilation issues may fail.]) > SED_EXTENDED_RE_FLAG='' > fi > fi > > Thoughts? > > Rob > >
